Sourdough Oatmeal Cream Pie Recipe

American Dessert

Sourdough Oatmeal Cream Pies

Soft, chewy oatmeal cookies with a subtle sourdough tang sandwiched around a billowy, marshmallow-kissed vanilla cream filling that makes every bite completely irresistible.

Imagine biting into a sandwich cookie where the outside is thick, chewy, and warmly spiced with cinnamon and brown sugar, and the inside is a cloud of sweet, fluffy vanilla cream that somehow manages to feel both nostalgic and completely new. That is exactly what these Sourdough Oatmeal Cream Pies deliver. The sourdough discard woven into the oatmeal cookie dough adds a gentle, barely-there tang that deepens the flavor in a way that is hard to put your finger on but impossible to ignore. It rounds out the sweetness, adds a faint earthiness, and gives these cookies a complexity that the classic store-bought version simply cannot match. The aroma as they bake, warm oats, brown butter, cinnamon, and that faint fermented note from the starter, fills the whole kitchen and makes waiting for them to cool genuinely difficult.

These cookies are perfect for baking when you have sourdough discard sitting in the fridge and want to do something truly special with it beyond yet another batch of pancakes. They are wonderful for holiday cookie boxes, bake sales, lunchboxes, after-school snacks, and any occasion where you want to hand someone something homemade that will genuinely make their day. Because the cookies and filling can both be made ahead and assembled right before serving, they are also a smart choice when you are entertaining and want to get most of the work done in advance.

I started making these after years of reaching for the Little Debbie version at the gas station during road trips and wondering if I could recreate that magic at home with a little sourdough twist. After a dozen test batches, this version became the one my whole family unanimously declared better than the original. The discard is the secret weapon here, and if you have never baked with it before, this recipe is the absolute best introduction.

Recipe at a Glance

⏱Prep Time30 mins

🔥Cook Time14 mins

🕐Total Time1 hr 30 mins

🍰Servings12 sandwich cookies

🇺🇸CuisineAmerican

🔢Calories~385 per sandwich cookie

Ingredients

Oatmeal Cookie Dough

1 cup (2 sticks) unsalted butter, softened to room temperature

1 cup packed dark brown sugar

1/2 cup granulated sugar

2 large eggs, room temperature

1/2 cup sourdough discard, unfed and room temperature

2 teaspoons pure vanilla extract

1 1/2 cups all-purpose flour

1 teaspoon baking soda

1 teaspoon ground cinnamon

1/2 teaspoon ground nutmeg

1/2 teaspoon fine sea salt

3 cups old-fashioned rolled oats (not quick oats)

1 tablespoon molasses

Marshmallow Vanilla Cream Filling

1/2 cup (1 stick) unsalted butter, softened to room temperature

1 1/2 cups powdered sugar, sifted

One 7-ounce jar marshmallow creme (such as Jet-Puffed Fluff)

2 teaspoons pure vanilla extract

1/4 teaspoon fine sea salt

1 to 2 tablespoons heavy cream, as needed for consistency

Substitutions & Variations

★Quick oats can substitute for old-fashioned rolled oats if that is what you have, though the texture of the finished cookies will be slightly softer and less chewy with less visible oat structure.

★If you do not have sourdough discard on hand, substitute with 1/4 cup plain whole-milk yogurt plus 1/4 cup all-purpose flour whisked together, which mimics the tang and moisture contribution of the discard.

★Dark brown sugar can be swapped for light brown sugar in equal amounts, though the cookies will have a slightly milder molasses flavor and a slightly less deep color.

★The marshmallow creme in the filling can be replaced with 1 cup of store-bought or homemade meringue for a lighter, less sweet filling with a slightly more sophisticated flavor.

★For a dairy-free version, use vegan butter sticks in both the cookies and the filling, replace the heavy cream with full-fat coconut cream, and use a dairy-free marshmallow creme.

★You can add 1/2 cup of raisins or mini chocolate chips to the cookie dough for a fun variation, though the classic plain oatmeal cookie version is the most authentic base for the cream filling.

Step-by-Step Instructions

1

Prep Your Workspace

Preheat your oven to 350 degrees Fahrenheit and line three large baking sheets with parchment paper or silicone baking mats. Pull your butter, eggs, and sourdough discard out of the refrigerator at least 45 minutes before you start so everything is genuinely at room temperature. Room temperature ingredients cream together much more smoothly and help the cookies bake up evenly without spreading too much or staying too puffy in the center.

2

Cream Butter and Sugars

In a large mixing bowl using a hand mixer, or in a stand mixer fitted with the paddle attachment, beat the softened butter, dark brown sugar, and granulated sugar together on medium-high speed for a full 3 to 4 minutes. You want the mixture to look noticeably lighter in color, very fluffy, and almost mousse-like. This extended creaming step is what gives the cookies their tender, chewy interior rather than a dense or cakey texture, so resist the urge to rush it.

3

Add Eggs, Discard, Vanilla, and Molasses

Add the eggs one at a time on medium speed, letting each one incorporate fully before adding the next. Scrape down the sides of the bowl with a rubber spatula. Add the sourdough discard, vanilla extract, and molasses and mix on medium speed until just combined. The batter may look slightly curdled at this point, which is completely normal and will come together once the dry ingredients are added. The sourdough discard should be at room temperature and unfed for the best flavor contribution.

4

Mix the Dry Ingredients

In a separate medium bowl, whisk together the all-purpose flour, baking soda, cinnamon, nutmeg, and salt until evenly combined. Add the dry ingredients to the wet mixture on the lowest speed setting and mix until just a few streaks of flour remain. Do not overmix at this stage because developing too much gluten will make the cookies tough rather than tender and chewy.

5

Fold In the Oats

Add the rolled oats to the bowl and fold them in by hand using a sturdy rubber spatula until fully and evenly incorporated throughout the dough. Make sure to scrape all the way down to the bottom of the bowl where dry flour and oats tend to hide. The finished dough will be thick, slightly sticky, and packed with oats. If it feels unusually loose or wet, refrigerate it for 20 minutes before scooping.

6

Portion the Cookies

Using a medium cookie scoop or a heaping 2-tablespoon measure, portion the dough into balls and place them about 2 inches apart on the prepared baking sheets. You should get approximately 24 cookies, which will pair up into 12 sandwich cookies. For evenly sized sandwiches, use a kitchen scale to portion dough balls that each weigh about 40 grams. Gently flatten each ball slightly with the palm of your hand so they spread evenly into rounds rather than staying too domed.

7

Bake the Cookies

Bake one sheet at a time on the center rack for 12 to 14 minutes, until the edges are set and lightly golden and the centers still look slightly underdone and soft. The cookies will firm up considerably as they cool, so pulling them at this stage is intentional and gives you that signature chewy texture rather than a crispy, overbaked cookie. Rotate the baking sheet halfway through the bake time if your oven has hot spots.

8

Cool Completely on a Rack

Allow the cookies to cool on the baking sheet for exactly 5 minutes before transferring them to a wire cooling rack. Let them cool completely to room temperature before assembling the sandwiches, which takes about 30 to 40 minutes. Assembling warm cookies will cause the cream filling to melt and squeeze out the sides. Use this cooling time to make the filling.

9

Make the Cream Filling

In a large bowl using a hand mixer, or in a stand mixer fitted with the whisk attachment, beat the softened butter on medium-high speed for about 2 minutes until pale and fluffy. Add the sifted powdered sugar one half-cup at a time, mixing on low after each addition to prevent a sugar cloud. Once all the sugar is incorporated, add the marshmallow creme, vanilla extract, and salt and beat on medium-high for a full 2 to 3 minutes until the filling is very light, smooth, and almost mousse-like. Add a tablespoon of heavy cream if the filling seems too stiff to spread comfortably, and beat again.

10

Match and Assemble the Sandwiches

Before filling, pair up the cookies by size so each sandwich has two matching cookies. Turn half the cookies upside down on your work surface so the flat bottoms face up. Spoon or pipe about 2 heaping tablespoons of filling onto the flat side of each bottom cookie, spreading it nearly to the edges but leaving a small border. Gently press a matching cookie on top, flat side down, and press lightly so the filling spreads just to the edges in an even layer. Avoid pressing so hard that the filling squeezes out the sides completely.

11

Rest Before Serving

Set the assembled sandwich cookies on a clean parchment-lined surface and let them rest at room temperature for at least 15 to 20 minutes before serving. This short resting time allows the filling to slightly firm up and bond with the cookies, which makes each bite cleaner and more cohesive rather than having the filling slide out the sides. If you are making them ahead, refrigerate the assembled sandwiches and bring them back to room temperature for 15 minutes before serving for the best texture.

Pro Baker Tips

✓Use old-fashioned rolled oats rather than quick oats for the best chew and texture. Quick oats absorb more moisture and turn the cookies softer and more cake-like rather than hearty and chewy.

✓Your sourdough discard does not need to be fresh or recently fed for this recipe. Discard that has been stored in the refrigerator for up to two weeks works perfectly and actually contributes a deeper tang.

✓Do not skip the molasses in the cookie dough. It is only 1 tablespoon, but it adds a warm, dark complexity that makes the cookies taste much more interesting and far less one-dimensional.

✓Weigh your dough portions on a kitchen scale for evenly matched cookie pairs. Mismatched cookies make lopsided sandwiches that are harder to bite into cleanly.

✓Make sure the butter in the filling is fully softened, not just slightly soft. Cold butter will leave the filling grainy and lumpy no matter how long you beat it.

✓If the filling becomes too soft while you are assembling and starts sliding off the cookies, refrigerate it for 10 to 15 minutes to firm it back up before continuing.

Storage & Serving Notes

◆Store assembled sandwich cookies in an airtight container at room temperature for up to 2 days. The cookies will soften slightly as they sit, which most people find makes them even better.

◆For longer storage, keep assembled sandwiches in an airtight container in the refrigerator for up to 5 days. Let them sit at room temperature for 15 minutes before eating for the best filling texture.

◆Unassembled baked cookies can be stored in an airtight container at room temperature for up to 4 days, and the filling can be refrigerated separately in an airtight container for up to 1 week. Re-whip the filling briefly before using.

◆Assembled sandwich cookies freeze well for up to 2 months. Wrap each one individually in plastic wrap, place in a freezer-safe bag, and thaw at room temperature for about 1 hour before serving.

◆The raw cookie dough can be portioned into balls, frozen on a baking sheet until solid, then transferred to a freezer bag and stored for up to 3 months. Bake from frozen at 350 degrees Fahrenheit and add 2 to 3 extra minutes to the bake time.

Serving Suggestions

These sandwich cookies are a total showstopper on their own, but a few fun ideas can make them even more memorable.

›Serve alongside a cold glass of whole milk or a creamy vanilla latte for the most classically satisfying pairing imaginable

›Stack three or four in a treat bag tied with a ribbon for a charming, homemade gift that anyone would be thrilled to receive

›Arrange on a tiered cookie stand at a holiday dessert table alongside other sandwich cookies for a beautiful and generous spread

›Crumble one or two over a bowl of vanilla ice cream for an easy, indulgent dessert that tastes like a deconstructed cookie sundae

›Pack individually wrapped in lunchboxes or picnic baskets as a special treat that holds up well and travels without falling apart

Frequently Asked Questions

Does the sourdough flavor come through strongly in the finished cookie?

No, the sourdough flavor is very subtle and works more as a background note than a prominent flavor. Most people cannot identify it as sourdough at all but will notice the cookies taste more complex and interesting than a standard oatmeal cookie. The tang is mild enough that even people who claim not to like sourdough consistently enjoy these cookies without realizing the discard is in there.

Can I use active bubbly starter instead of discard?

Yes, active starter works just as well as discard in this recipe. The flavor contribution will be very similar since the starter is not leavening the cookies anyway. The baking soda in the dough handles all the rise, so whether your starter is freshly fed and active or has been sitting unfed in the refrigerator for a week, either will give you great results.

Why are my cookies spreading too thin and flat?

Flat, thin cookies are almost always caused by butter that was too soft or even slightly melted before creaming, dough that was not chilled before baking, or too much sourdough discard making the dough overly wet. Make sure your butter is softened but still cool enough to hold a thumbprint without your thumb sinking all the way through. If the dough feels sticky or loose after mixing, refrigerate it for 30 minutes before scooping and baking.

Can I make the cookies and filling days ahead?

Absolutely. The baked cookies keep well in an airtight container at room temperature for up to 4 days, and the filling keeps in the refrigerator for up to 1 week. When you are ready to assemble, bring the filling to room temperature and re-whip it briefly with a hand mixer to restore its fluffy consistency, then sandwich and serve. This make-ahead approach actually works really well for entertaining or holiday baking.

My filling is too sweet. How do I balance it?

If the filling tastes too sweet for your preference, add a small pinch of additional salt and a teaspoon of fresh lemon juice, then beat again. Both of these additions cut through the sweetness without altering the overall flavor profile significantly. You can also reduce the powdered sugar by up to 1/4 cup and the filling will still be plenty sweet and spreadable thanks to the marshmallow creme.

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Go Make It!

Once you make a batch of these Sourdough Oatmeal Cream Pies and watch them disappear from the plate in record time, you will never look at your jar of sourdough discard the same way again. These cookies are chewy, warmly spiced, filled with creamy dreamy vanilla goodness, and just different enough from the classic to feel like something genuinely special. So pull that discard from the fridge, soften your butter, and get ready to bake something your whole kitchen will smell amazing for hours. Everyone who gets one of these is going to ask you for the recipe.