This Oatmeal Cream Pie Cake transforms the nostalgic flavor of the classic sandwich cookie into an impressive layered dessert. Soft, spiced oatmeal cake layers are paired with a fluffy marshmallow cream filling, creating a cake that is rich, comforting, and perfect for gatherings or special occasions.
Why You’ll Love This Recipe
This cake delivers deep, cozy flavors from oats, cinnamon, and brown sugar while staying incredibly moist. The cream filling is light and smooth, balancing the hearty cake layers beautifully. It is a great make-ahead dessert, slices cleanly, and feels both nostalgic and bakery-worthy at the same time.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
Oatmeal Cake Layers
2 cups old-fashioned oats
2 cups boiling water
1½ cups unsalted butter, softened
1½ cups brown sugar
¾ cup granulated sugar
4 large eggs, room temperature
2 teaspoons vanilla extract
1 tablespoon molasses
3 cups all-purpose flour
1½ teaspoons baking soda
2 teaspoons ground cinnamon
½ teaspoon ground nutmeg
1 teaspoon salt
Preheat the oven to 350°F (175°C). Grease and line three 8-inch round cake pans.
Place the oats in a heatproof bowl and pour the boiling water over them. Stir and let sit for 15 minutes until softened.
In a large bowl, cream the butter, brown sugar, and granulated sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Mix in the vanilla extract and molasses.
Stir the softened oats and any remaining liquid into the batter.
In a separate bowl, whisk together the flour, baking soda, cinnamon, nutmeg, and salt. Add the dry ingredients to the batter and mix just until combined.
Divide the batter evenly among the prepared pans. Bake for 22 to 26 minutes, or until a toothpick inserted in the center comes out clean. Allow the layers to cool completely.
For the filling, beat the butter until creamy. Gradually add the powdered sugar and beat until smooth. Mix in the marshmallow fluff and vanilla extract. Beat for 3 to 4 minutes until very fluffy, adding heavy cream as needed for a light texture.
To assemble, place one cake layer on a serving plate and spread an even layer of cream filling on top. Add the second layer and repeat. Top with the final layer. Frost the top with remaining filling, and frost the sides with cinnamon buttercream if desired.
Servings and timing
Servings: 12 slices
Preparation time: 30 minutes
Baking time: 22 to 26 minutes
Cooling and assembly time: 40 minutes
Total time: approximately 1 hour and 40 minutes
Variations
Add chopped toasted walnuts or pecans to the batter for extra texture.
Replace cinnamon with pumpkin spice for a seasonal twist.
Use a thin layer of cinnamon buttercream between layers for a richer filling.
Brush each cake layer lightly with vanilla milk for extra moisture.
Storage/Reheating
Store the cake covered in the refrigerator for up to 4 days. Let slices sit at room temperature for 20 minutes before serving for the best texture. This cake does not require reheating, but can be enjoyed slightly chilled or at room temperature.
FAQs
Can I make this cake ahead of time?
Yes, the cake layers can be baked a day in advance and wrapped tightly before assembling.
Can I freeze the cake?
You can freeze unfrosted cake layers for up to 2 months. Thaw completely before frosting.
What can I use instead of marshmallow fluff?
A stabilized whipped cream frosting can be used, but the flavor will be less traditional.
Can I use quick oats?
Old-fashioned oats are recommended for texture, but quick oats can work if needed.
How do I keep the cake layers from crumbling?
Allow the layers to cool fully and chill briefly before assembling.
Can I make this in a different pan size?
Yes, two 9-inch pans can be used; adjust baking time slightly.
Is the molasses required?
It is optional but adds depth and classic oatmeal flavor.
Can I reduce the sweetness?
You may slightly reduce the powdered sugar in the filling, but texture may change.
What garnish works best?
Mini oatmeal-style cookies, oat crumble, or a light dusting of cinnamon work well.
How do I get clean slices?
Chill the cake for 30 minutes and use a sharp knife wiped clean between cuts.
Conclusion
Oatmeal Cream Pie Cake is a comforting, crowd-pleasing dessert that combines nostalgic flavors with an elegant presentation. With its moist layers and fluffy filling, it is a perfect choice when you want a cake that feels both familiar and special.
This Oatmeal Cream Pie Cake transforms the nostalgic flavor of the classic snack into a layered dessert with spiced, moist oatmeal cake and fluffy marshmallow cream filling. It’s rich, comforting, and perfect for special occasions.
Ingredients
2 cups old-fashioned oats
2 cups boiling water
1½ cups unsalted butter, softened
1½ cups brown sugar
¾ cup granulated sugar
4 large eggs, room temperature
2 teaspoons vanilla extract
1 tablespoon molasses
3 cups all-purpose flour
1½ teaspoons baking soda
2 teaspoons ground cinnamon
½ teaspoon ground nutmeg
1 teaspoon salt
1½ cups unsalted butter, softened (for filling)
3 cups powdered sugar
1½ cups marshmallow fluff
2 teaspoons vanilla extract (for filling)
2 to 4 tablespoons heavy cream
¾ cup unsalted butter, softened (optional buttercream)
