This delicious Banana Crumb Cake combines two classics: banana bread and crumb cake! Moist banana cake topped with a buttery brown sugar crumble and vanilla icing.
We’re adding a crumbly topping to our banana bread because it’s a fact that everything is better with a crumbly topping. And while we’re at it, we’re also adding a generous drizzle of vanilla icing. Yum!
Two of my most popular recipes are Banana Bread and Banana Nut Muffins, so I know you love baking with bananas. This cake is perfect for breakfast, dessert, or snacking. Does a big square slice alongside a glass of iced coffee make for the BEST EVER afternoon snack? It sure does!
What makes this recipe the best?
- Banana cake – The base of this recipe is a sweet, soft, moist banana cake that is baked in a 9-inch square pan.
- Crumb topping – A buttery, brown sugar crumble adorns the top of the cake. This is a simple mixture of flour, brown sugar, salt, and melted butter. Feel free to add cinnamon if you’d like.
- Vanilla icing – The perfect finishing touch! A drizzle of sweet vanilla icing made from powdered sugar, milk, and a splash of vanilla extract.
Recipe tips and storage
- Make sure to use overripe bananas. They’ll be extra sweet and they’ll mash-up really easily. This recipes uses 1 cup of mashed bananas, which is about 2 large or 3 medium-sized bananas.
- Use a 9×9 baking pan for even baking. This is my preferred pan size for this recipe, as well as my banana bread recipe. Why? I find that the cake bakes evenly without the risk of the edges getting dried out before the center is baked through. If you choose to make this recipe in an 8×8 pan, you’ll need to adjust the bake time by adding approximately 8-10 minutes. If the top starts to get dark you can loosely tent it with foil.
- This cake can be stored tightly covered at room temp for up to 2 days. Leftovers can also be frozen.
- If you’re out of sour cream you can try one of these Sour Cream Substitutes.
MORE BANANA RECIPES
- BANANA CAKE WITH CREAM CHEESE FROSTING
- BANANA BUNDT CAKE
- CHOCOLATE CHIP BANANA BREAD
- HOMEMADE BANANA PUDDING
- BANANA CHOCOLATE CHIP MUFFINS
Banana Crumb Cake
- ¾ cup all purpose flour
- ¾ cup light brown sugar
- ¼ teaspoon salt
- 6 tablespoons unsalted butter, melted
- 1 teaspoon ground cinnamon, optional
- 1-⅓ cups all purpose flour
- 1 teaspoon baking soda
- ¼ teaspoon salt
- ½ teaspoon ground cinnamon
- 6 tablespoons unsalted butter, softened
- ¾ cup granulated sugar
- 1 large egg
- 1 teaspoon pure vanilla extract
- 1 cup mashed very ripe bananas, (about 3 bananas)
- ⅓ cup sour cream
- ¾ cup powdered sugar
- 1 tablespoon half and half or milk
- ¼ teaspoon vanilla extract
- Combine, flour, brown sugar, salt, and cinnamon (if using) in a medium bowl. Pour in melted butter and stir until moist crumbs form. Place in the freezer for about 10 minutes while you proceed with the cake batter.
- Preheat oven to 350°F with a rack in the middle of the oven. Butter or spray a 9x9* baking pan.
- In a medium bowl, whisk the flour, baking soda, salt, and cinnamon (if using). Set aside.
- Using a hand mixer or stand mixer fitted with the paddle attachment, beat the butter and sugar for two minutes, until light and fluffy. Add egg and vanilla and beat to combine, scraping the sides of the bowl as necessary. Add mashed bananas and beat until combined, scraping the sides of the bowl as necessary (the mixture might look curdled; that's ok).
- Add half of the dry ingredients, beating until combined. Add the sour cream, followed by the remaining dry ingredients, beating between each addition.
- Pour the batter into the prepared pan and spread it into an even layer. Top with the crumb mixture. As you're sprinkling the crumb mixture over the top, pinch some of it between your fingers to create larger crumbs.
- Bake the cake for 32-36 minutes, until a toothpick inserted into the center comes out clean. Cool cake on a wire rack, then drizzle with icing.
- Whisk all ingredients until smooth. Adjust the consistency by adding more powdered sugar to thicken or more milk to thin. Drizzle over the cooled cake.