Sweet Potato Casserole Cake
Serves 24
30 mins prep
40 mins cook
70 mins total
Sweet potato cake layers with a brown butter brown sugar filling covered in a toasted marshmallow fluff meringue frosting.
Sweet potato cake
Brown sugar filling
Marshmallow fluff meringue frosting
Scan QR code to shop the ingredients!
Get ingredients delivered
Scan QR code to shop the ingredients!
Get ingredients delivered
Do ahead
Preheat the oven to 350°F. Grease two 8-inch round cake tins and place circles of parchment paper in the bottoms.
Make the cake layers
Whisk together the flour, baking powder, baking soda, salt and cinnamon. Set aside.
In another bowl, combine the brown sugar, granulated sugar, eggs, oil, mashed sweet potatoes and vanilla.
Add the dry ingredients to the wet ingredients and mix just until combined. Do not overmix.
Split the batter evenly between the prepared pans.
Bake for 25-35 minutes. A toothpick or cake tester should come out clean, when it is done.
Let cool in the tins for 20 minutes before tipping out onto a wire rack to cool completely.
Make the filling
In a medium saucepan over medium heat brown the butter. This may take a few minutes. The butter will become foamy and sputter. Pull it from the heat as soon as you see the milk solids take on a brown, nutty color. Transfer to a heat proof bowl.
Add the cream, brown sugar and vanilla to the bowl. Microwave in bursts until the sugar is dissolved. Allow to cool completely.
In the bowl of a stand mixer, or with hand beaters, beat together the cooled mixture with the powdered sugar.
Make the marshmallow fluff frosting
Prep your mixing bowls and beaters by wiping them down with vinegar to ensure they are oil-free so the meringue doesn’t fail.
Place water, sugar and corn syrup in a medium saucepan over medium-high. Stir to combine and then do not stir any longer to prevent crystals forming.
Place the egg whites and cream of tartar in the bowl of a stand mixer.
When the sugar syrup reaches 225°F, start whipping the egg whites on medium-low.
When the sugar syrup reaches 240°F, remove it from the heat. Turn the mixer to medium and slowly stream in the sugar syrup into the whites.
When the syrup is in, turn the mixer to medium-high and continue whipping for 7-8 minutes, or until the mixture is thick and fluffy.
Add in the vanilla and whip until the fluff cools completely.
Use right away or transfer into an airtight container and store for up to 2 weeks at room temperature.
Assemble the cake
Trim the tops of the cakes to be flat, if necessary.
Place the first layer of cake onto an 8-inch cake board or cake platter with a small smear of the frosting or filling to hold it in place.
Pipe or spread the brown butter brown sugar filling on top of the first cake layer, using as much or as little as you’d like.
Place the top layer of cake on top of the filling. Give the cake a gentle press on top to push the cake into the filling.
Pipe or spread the marshmallow meringue fluff all over the cake, smoothing with an offset spatula. Make swoops and swirls in the frosting with the tip of the offset spatula or with the back of a spoon.
Use a kitchen torch to toast the outside of the cake, if desired.
