Banana Nut Sheet Cake
Mar 21, 2025
Ingredients:
For the Frosting:
- 3/4 cup (1 1/2 sticks) unsalted butter, plus 2 tablespoons
- 3 cups powdered sugar
- 1 teaspoon vanilla bean paste
- 1/4 cup whole milk
- 1/2 teaspoon cinnamon
- a pinch of salt
For the Cake:
- 2 cups all purpose flour
- 1 teaspoon cinnamon
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1/2 cup (1 stick) unsalted butter
- 1 cup sugar
- 1/2 cup light brown sugar
- 1 teaspoon vanilla bean paste
- 1 cup sour cream
- 3 large bananas, smashed
- 2 eggs
- 1/2 cup chopped walnuts
Directions:
For the Cake:
- Preheat the oven to 350F. Grease a jelly roll pan and set aside.
- Add all the butter (for both the cake and the frosting, minus the two tablespoons) to a medium saucepan over medium heat. Cook until the butter begins to smell aromatic and turns a nice amber color. Remove from heat and add 1/2 cup of the butter to a medium mixing bowl and set aside. Add the two tablespoons to the remaining 3/4 cups of brown butter and stir it in until fully melted. Add this butter to the freezer for later for the frosting.
- In a separate medium mixing bowl, whisk together the flour, baking soda, salt and cinnamon. Add the walnuts to a small bowl and coat with one tablespoon of the flour mixture. Set aside.
- Add the sugar and brown sugar to the bowl with the 1/2 cup of brown butter. Whisk together until fully incorporated. Whisk in the sour cream and vanilla beam paste.
- Whisk in the smashed bananas and then the eggs.
- Add the dry mixture into the wet and mix together until just incorporated, making sure not to over-mix. Fold in the walnuts.
- Add the batter to your prepared pan and spread into an even layer with a rubber spatula. Bake for 25-30 minutes until a toothpick inserted comes out clean. Let cool completely before frosting.
For the Frosting:
- Remove your solidified butter from the freezer and add to a medium mixing bowl. Beat with an electric mixer for about 3 minutes until light and fluffy.
- Beat in the powdered sugar and milk. Scrape the bowl as needed. If the frosting is still a little too thick, you can add a tablespoon of milk at a time until you reach a spreadable consistency.
- Beat in the vanilla, salt and cinnamon.
- Spread the frosting in an even layer over your cooled cake. Top with additional walnuts and chopped bananas, if desired.
*Store in an airtight container at room temperature for up to three days. Store in an airtight container in the fridge for up to one week.
*It won't be as pretty, but if you want to spread the frosting over a couple of slices while they are still warm, it tastes better. You can even serve warm with some ice cream. The cake will crumble if you cut it warm and the frosting will melt, so just keep that in mind if you're wanting something a little nicer looking. But if you don't care what it looks like, the cake is better this way in my opinion.