Soft, chewy oatmeal cookies sandwiching a luscious, creamy filling—these Oatmeal Cream Pies are a nostalgic treat with a homemade twist. The cookies are perfectly spiced with cinnamon and brown sugar, offering a warm, comforting flavor that pairs beautifully with the velvety vanilla cream.
In just under two hours, you can create a batch of 20 pies that are ideal for sharing or savoring one by one. Each bite delivers a delightful contrast of textures, from the tender cookie to the smooth, rich center, making them irresistible for any occasion.
With a prep time of 90 minutes and a quick 20-minute bake, these pies are surprisingly simple to make yet feel indulgent. Packed with wholesome oats and a hint of sweetness, they’re a satisfying treat that balances comfort and decadence. Whether enjoyed as an afternoon snack or a dessert, these Oatmeal Cream Pies are sure to bring smiles and warm memories with every bite.
Ingredients for Oatmeal Cream Pies
- For Cookies:
- 1 cup (226 g) unsalted butter, melted and cooled (ensure it’s no longer warm to the touch)
- 1 cup (200 g) dark brown sugar, firmly packed
- ½ cup (100 g) granulated sugar
- 2 Tablespoons unsulphured molasses
- 2 large eggs, room temperature preferred
- 1 ½ teaspoons vanilla extract
- 2 cups (250 g) all-purpose flour
- 2 teaspoons cornstarch
- 1 ¼ teaspoon baking soda
- ¾ teaspoon ground cinnamon
- ¾ teaspoon table salt
- 2 cups (180 g) instant/quick oats
- For Marshmallow Cream Filling:
- 6 large egg whites (210 g) (avoid carton egg whites for best results)
- 1 ½ cups (300 g) granulated sugar
- ½ teaspoon cream of tartar
- ¼ teaspoon salt
- 1 ½ teaspoons vanilla extract
Step-by-Step Instructions
- Prepare the Cookies:
- Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper. Set aside.
- In a large bowl, combine melted butter, dark brown sugar, granulated sugar, and molasses. Stir well by hand until fully mixed.
- Add eggs and vanilla extract to the butter mixture and stir until combined.
- In a separate bowl, whisk together flour, cornstarch, baking soda, cinnamon, and salt until evenly combined.
- Gradually stir the dry ingredients into the butter mixture until thoroughly incorporated.
- Fold in the oats until evenly distributed throughout the dough.
- Drop dough by level 1 ½-Tablespoon scoops onto the prepared baking sheet, spacing them about 2 inches apart.
- Bake for 10 minutes or until the edges are golden brown. Allow cookies to cool completely on the baking sheet.
- Make the Marshmallow Cream Filling:
- Prepare a double boiler: Fill a medium saucepan with 1 ½-2 inches (4-5 cm) of water and bring to a simmer over medium-low heat.
- In the clean, dry, and grease-free bowl of a stand mixer, combine egg whites, sugar, cream of tartar, and salt. Whisk to combine.
- Place the mixing bowl over the simmering water, ensuring the bowl doesn’t touch the water. Whisk constantly until the sugar dissolves and the mixture reaches at least 160°F (70°C). Test by rubbing a bit between your fingers—it should feel smooth, not gritty.
- Remove the bowl from heat and attach it to the stand mixer. Using the whisk attachment, beat on medium-high speed until the mixture becomes thick, glossy, and forms stiff peaks (5-10 minutes).
- Stir in vanilla extract until fully incorporated.
- Assemble the Oatmeal Cream Pies:
- Once the cookies are completely cooled, scoop about 2 Tablespoons of marshmallow cream filling onto the bottom of one cookie.
- Top with another cookie to create a sandwich. Repeat with remaining cookies and filling.
- Serve and enjoy your homemade Oatmeal Cream Pies!
Storage and Reheating Tips
Store your Oatmeal Cream Pies in an airtight container at room temperature for up to 3 days. For longer storage, place them in the fridge for up to a week or freeze for up to 3 months. If frozen, let them thaw at room temperature before enjoying. To refresh the cookies, warm them in the microwave for 5-10 seconds for a soft, gooey texture.
Time-Saving Hacks
If you’re short on time, use store-bought marshmallow fluff instead of making the filling from scratch. For the cookies, prepare the dough ahead of time and refrigerate it for up to 2 days—just let it soften slightly before scooping and baking. You can also bake the cookies in batches while prepping the filling to save time.
Recipe Variations to Try
Swap the marshmallow filling for a classic buttercream or cream cheese frosting for a different twist. Add a handful of chocolate chips or raisins to the cookie dough for extra flavor. For a nutty crunch, mix in chopped walnuts or pecans. If you prefer a gluten-free version, use a 1:1 gluten-free flour blend and certified gluten-free oats.
Equipment Guidance for Success
A stand mixer is highly recommended for the marshmallow filling to achieve stiff peaks efficiently. If you don’t have one, an electric hand mixer will work, but be prepared for a longer mixing time. Use a double boiler setup for the filling to ensure the sugar dissolves properly. A cookie scoop ensures evenly sized cookies for perfect sandwiches.
Common Questions Answered
Can I use old-fashioned oats instead of quick oats?
Yes, but the texture will be slightly chewier.
What if I don’t have cream of tartar?
You can omit it, but it helps stabilize the egg whites.
Can I use carton egg whites?
It’s not recommended, as they may not whip properly. Stick to fresh egg whites for the best results.
Oatmeal Cream Pies
Ingredients
For Cookies
- 1 cup unsalted butter melted and cooled until no longer warm to the touch
- 1 cup dark brown sugar firmly packed
- ½ cup granulated sugar
- 2 Tablespoons unsulphured molasses
- 2 large eggs room temperature preferred
- 1 ½ teaspoons vanilla extract
- 2 cups all-purpose flour
- 2 teaspoons cornstarch
- 1 ¼ teaspoon baking soda
- ¾ teaspoon ground cinnamon
- ¾ teaspoon table salt
- 2 cups instant/quick oats
For Marshmallow Cream Filling
- 6 large egg whites (I do not recommend using egg whites from a carton, as people have reported mixed results with these)
- 1 ½ cups granulated sugar
- ½ teaspoon cream of tartar
- ¼ teaspoon salt
- 1 ½ teaspoons vanilla extract
Instructions
- For CookiesPreheat oven to 350F (175C) and line a baking sheet with parchment paper. Set aside.
- Combine butter, sugars, and molasses and stir well (I do not use an electric mixer for this recipe and just stir everything by hand).1 cup (226 g) unsalted butter, 1 cup (200 g) dark brown sugar, ½ cup (100 g) granulated sugar, 2 Tablespoons unsulphured molasses
- Add egg and vanilla extract and stir to combine.2 large eggs, 1 ½ teaspoons vanilla extract
- In a separate bowl, whisk together flour, cornstarch, baking soda, cinnamon, and table salt until completely combined.2 cups (250 g) all-purpose flour, 2 teaspoons cornstarch, 1 ¼ teaspoon baking soda, ¾ teaspoon ground cinnamon, ¾ teaspoon table salt
- Gradually stir dry ingredients into butter mixture until thoroughly combined.
- Stir in oats until well-distributed.2 cups (180 g) instant/quick oats
- Drop batter by level 1 ½-Tablespoon-sized scoop onto prepared baking sheet and bake on 350F (175C) for 10 minutes or until edges are beginning to turn golden brown. Allow cookies to cool completely on baking sheet before filling.
- For Marshmallow Cream Filling (see note for alternative filling options)Before you begin: You will need a double boiler for this recipe. I recommend using the metal bowl of a stand mixer and a saucepan that is large enough to support the bowl without it touching the bottom of the pan. While this recipe can be prepped with an electric hand mixer, please note that it will be quite an arm workout and will take a long time and I recommend using a stand mixer if you have one).
- In the completely clean, dry and grease-free bowl of a stand mixer, combine egg whites, sugar, cream of tartar and salt and whisk to combine.6 (210 g) large egg whites, 1 ½ cups (300 g) granulated sugar, ½ teaspoon cream of tartar, ¼ teaspoon salt
- Bring 1 ½-2” (4-5cm) of water to a simmer over medium-low in a medium-sized saucepan (use a saucepan that your mixing bowl will fit in without touching the bottom of the pan).
- Place mixing bowl over simmering water and whisk constantly until the sugar is dissolved (if you rub a small bit of the syrup between your fingers (be careful, it’s hot!) it should no longer feel gritty at all) and the mixture reaches at least 160F (70C).
- Remove mixing bowl from heat and fit it into your mixer. Using a whisk attachment, beat the egg whites on medium-high speed until mixture becomes thick and glossy and you have billowy stiff peaks. This typically takes approximately 5-10 minutes with a stand mixer but will take longer if you are using a hand mixer with beaters.
- Stir in vanilla extract.1 ½ teaspoons vanilla extract
- AssemblyOnce cookies have cooled, scoop a generous portion (I use about 2 Tablespoons) of marshmallow cream filling onto the bottom of one cookie. Top with another cookie to make a sandwich/marshmallow cream pie. Serve and enjoy!