This cake captures the best fall flavors—perfect for Thanksgiving or any cozy gathering. Moist sweet potato cake layers use real baked sweet potatoes, each layer is filled with a rich pecan pie filling, and the whole cake is finished with a brown butter maple pecan buttercream. The combination is comforting and decadent without feeling heavy. If you love pies and cake hybrids, this one belongs on your rotation.
I developed and photographed this cake last October and initially considered saving it for a later cookbook, but its flavor felt too timely to wait. The recipe breaks down into three straightforward components—cake layers, pecan pie filling, and a brown butter-maple buttercream—and comes together more quickly than you might expect.
Sweet potato love
Sweet potato gives these cake layers a gentle, earthy sweetness that complements the pecan and maple elements. If you prefer a milder profile where pecan is the main note, you can substitute white cake layers and add a teaspoon of pecan flavoring to the batter, tasting and adjusting to your preference.
For convenience, you can bake sweet potatoes in the oven or microwave them until very soft. Remove the skin and mash or scrape the flesh into a bowl before incorporating it into the batter. Soft, well-cooked sweet potatoes blend smoothly and keep the cake tender and moist.
Pecan pie filling
The pecan pie filling is exactly what you expect from a classic pecan pie—sweet, nutty, and slightly sticky—but scaled down for use between cake layers. Instead of baking it in a pie shell, the filling comes together quickly on the stovetop. Stir the ingredients over medium heat until they thicken, then cool the mixture in a glass bowl in the refrigerator. The recipe yields about 1 cup of filling—enough for two thin layers spaced through the cake.
Tip: Toast pecans briefly before using them in both the filling and buttercream for a deeper, more toasty flavor.
Once cooled, the filling is easy to spread between the cake layers. For neat assembly, pipe a buttercream dam around the edge of each layer to keep the filling contained.
Browned buttercream bliss
This buttercream is the highlight: brown butter adds a nutty, caramel-like depth, while maple and pecan flavors create a layered, autumnal profile. The texture is rich but still pipeable, and it spreads beautifully over chilled cakes.
Start by browning a portion of the butter and letting it cool completely so it won’t melt the rest of the butter when combined. Pulse pecans in a food processor until they’re very fine—almost a paste—so they blend smoothly into the frosting and won’t clog piping tips. Use pure maple syrup or maple extract for the maple note; the recipe calls for a modest amount, but you can increase it if you prefer a stronger maple flavor.
If you want the dramatic ruffled finish shown in photos, a large piping tip is helpful and speeds the process. The buttercream also holds garnish well—arrange pecan halves on top for a classic presentation.
I hope you make this cake and enjoy the cozy, fall-inspired flavors as much as I do. If you bake it, I’d love to see your version—share a photo and spread the joy of seasonal baking!
xo and happy baking,
Mandy
Get the Recipe:
Sweet Potato Pecan Pie Cake
Pin Recipe
Leave a Review
Ingredients
Sweet Potato Cake Layers
- 20 oz (or three small) sweet potatoes
- 1 teaspoon cinnamon
- 3 whole eggs, room temperature
- 1/2 cup sour cream, room temperature
- 1/2 cup buttermilk, room temperature
- 1/2 cup vegetable oil
- 1 Tablespoon vanilla
- 1 box cake mix (yellow), I use Duncan Hines, but you can use a similar brand.
Brown Butter Maple Pecan Buttercream
- 4 sticks (2 cups) unsalted butter
- 1 cup pecans, pulsed to a powder in a food processor
- 1 teaspoon cinnamon
- 1 pinch salt
- 1 tablespoon maple extract
- 1/4 cup heavy cream
- 7-8 cups powdered sugar
Pecan Pie Filling
- 1 cup crushed pecans
- 1 whole egg
- 1/4 cup light corn syrup
- 1/4 cup brown sugar
- 1 teaspoon vanilla
- 1 pinch salt
- 1/2 teaspoon cinnamon
- 3 Tablespoons unsalted butter
Garnish
- 1 cup pecan halves
Instructions
Sweet Potato Cakes
-
Preheat oven to 325°F for convection or 350°F for conventional. Prepare three 6″ cake pans with shortening and flour and set aside.
-
Poke sweet potatoes several times with a fork and microwave about 7–8 minutes, or until fully soft. Scoop the cooked sweet potato flesh into a bowl and discard the skins.
-
In a large bowl, combine the sweet potato with the remaining wet cake ingredients (except the cake mix). Whisk by hand until smooth, then sift in the cake mix and stir until just combined—do not overmix. Divide batter among prepared pans and bake 30–32 minutes, or until centers are set. Cool completely, then wrap and freeze for at least two hours for easier assembly.
Pecan Pie Filling
-
Combine crushed pecans, egg, corn syrup, brown sugar, vanilla, salt, and cinnamon in a small saucepan. Heat over medium, stirring until the mixture bubbles and thickens. Stir in the butter, then transfer to a glass bowl to cool completely before using.
Brown Butter Maple Pecan Buttercream
-
Melt one stick of butter in a small saucepan over medium heat, stirring until it foams and begins to brown. Watch closely to avoid burning. Remove from heat and transfer to a glass bowl, scraping all the browned bits. Cool completely before using.
-
In the bowl of a stand mixer fitted with a paddle attachment, beat the remaining three sticks of butter together with the cooled browned butter on high until light and fluffy. Add salt, vanilla, finely pulsed pecans, maple extract, and heavy cream. Gradually add powdered sugar until incorporated. If needed, add a touch more cream for consistency. Beat on high for 2 minutes until the buttercream is light in texture and color.
Assembly
-
Place a cardboard cake round on a turntable and stack the chilled cake layers, piping a buttercream dam around the edge of each layer before adding the pecan pie filling so it stays contained. After stacking, crumb coat the cake and freeze briefly. Use a large piping tip to pipe ruffles around the top and sides, and finish with pecan halves as garnish.