If you grew up loving those classic Little Debbie Oatmeal Creme Pies, this homemade version will blow you away. The cookies are soft and chewy with just the right amount of spice, and the marshmallow buttercream is pillowy and sweet with a touch of vanilla.
They’re perfect for nostalgic bake sales, after-school treats, or just when you’re craving a soft sandwich cookie with a serious comfort factor.
Ingredients You’ll Need
For the oatmeal cookies:
- Butter: Softened unsalted butter makes for a tender, flavorful base.
- Brown sugar + granulated sugar: For rich sweetness and chew.
- Molasses: Adds depth and that classic cream pie flavor. Optional, but worth it!
- Eggs & vanilla: For moisture and flavor.
- Flour, baking soda & powder, cinnamon, salt: The perfect balance of rise and warm spice.
- Rolled oats: For texture—old-fashioned oats give the best result here.
For the marshmallow buttercream:
- Butter: Soft and creamy, forms the base of the filling.
- Powdered sugar: For structure and sweetness.
- Marshmallow creme: Store-bought or homemade (instructions included!).
- Vanilla & salt: To round out the flavor.
Tips for Success
- Chill your dough: Helps prevent spreading and gives the cookies a thick, soft texture.
- Don’t overbake: The cookies should look slightly underdone in the center when pulled—they’ll firm up as they cool.
- Use quick oats for slightly thicker cookies if you’d like less spread.
- Make ahead: You can chill the dough for up to 48 hours before baking. Filled cookies also store beautifully in the fridge!
Make-Ahead Tips & Prep Shortcuts
- Chill the dough in advance:
- You can prepare the dough up to 48 hours ahead. Keep it tightly covered in the fridge or scoop the dough onto a baking sheet and freeze in balls. Bake directly from chilled or frozen—just add 1–2 minutes to the bake time.
- Bake ahead:
- The cookies alone keep well in an airtight container for 2–3 days or can be frozen (unfilled) for up to 2 months. Let thaw before assembling.
- Make the filling in advance:
- The marshmallow buttercream can be made up to 3 days ahead. Store in the fridge in an airtight container and bring to room temp before spreading.
- Assemble ahead (short-term):
- Fully assembled cream pies can be stored in the fridge for 4–5 days in a sealed container. If making them for a party or event, assemble the day before for best texture.
Freeze for later:
Wrap individual assembled cookies tightly in plastic wrap and freeze for up to 1 month. Thaw at room temperature or pop them in the fridge overnight.
Storage
- Room Temp (unfilled cookies): Up to 3 days
- Refrigerated (assembled): 4–5 days in an airtight container
- Freezer:
- Cookie dough: 2 months
- Baked cookies: 2 months
- Fully assembled cream pies: 1 month (wrapped well)
FAQ
Q: Can I use quick oats?
Yes, but the texture will be softer and slightly less chewy. If you want thicker cookies with less spread, a 50/50 mix of quick and old-fashioned oats works well.
Q: I don’t have marshmallow creme—what can I substitute?
You can make the homemade version above or sub in 1 cup mini marshmallows gently melted with 1 tablespoon butter (then cooled) for a quick DIY option.
Q: Can I double the recipe?
Absolutely! These freeze great too, so you’ll be glad you did.
Homemade Oatmeal Cream Pies
Ingredients
For the oatmeal cookies:
- 1 cup (2 sticks) unsalted butter, softened
- ¾ cup packed brown sugar
- ½ cup granulated sugar
- ½ tablespoon molasses (optional, but adds great flavor)
- 2 large eggs
- 1 teaspoon vanilla extract
- 1½ cups all-purpose flour
- ½ teaspoon baking soda
- 1 teaspoon baking powder
- ½ teaspoon salt
- 1 teaspoon ground cinnamon
- 1¾ cups old-fashioned rolled oats
For the marshmallow buttercream filling:
- ½ cup (1 stick) unsalted butter, softened
- 1 cup powdered sugar
- 1 jar (7 oz) marshmallow creme (like Fluff or homemade see below)
- 1 teaspoon vanilla extract
- Pinch of salt
Homemade fluff for marshmallow buttercream (optional)
- 2 egg whites
- ½ cup granulated sugar
- ¼ teaspoon cream of tartar
- 1 teaspoon vanilla extract
Instructions
- Line two baking sheets with parchment paper. In a large bowl, cream the butter, brown sugar, and granulated sugar until light and fluffy, about 2 minutes. Mix in the eggs, molasses, and vanilla.
- In a separate bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon. Gradually add to the wet ingredients and mix until just combined. Stir in the oats until evenly incorporated.
- Cover the bowl and chill the dough for at least 30 minutes, or scoop dough onto baking sheets and chill the trays.
- Scoop dough (about 1½ tablespoons each) onto prepared baking sheets, spacing about 2 inches apart.
- Preheat oven to 350°F (175°C). Bake for 9–11 minutes, or until the edges are golden and the centers are just set. Do not overbake. Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
- Make the marshmallow creme (if using storebought, skip this step). In a heatproof bowl, combine egg whites, sugar, and cream of tartar. Place the bowl over a saucepan of simmering water (double boiler style), making sure the bowl doesn’t touch the water. Whisk constantly for 4–5 minutes, until the sugar dissolves and mixture reaches about 160°F. Transfer mixture to a stand mixer fitted with a whisk attachment. Beat on high speed for 6–8 minutes, or until stiff, glossy peaks form. Beat in the vanilla extract for 30 seconds.
- Prepare buttercream. In a medium bowl, combine the softened butter, powdered sugar, marshmallow creme, vanilla, and salt. Beat on medium speed for 2–3 minutes, until smooth and fluffy.
- Spread or pipe the cream filling onto the flat side of half the cookies. Top with the remaining cookies to create sandwiches. Enjoy!