Banana Crumb Cake with Cinnamon Streusel Topping

This soft and fluffy banana crumb cake is the kind of easy banana dessert that feels warm, cozy, and homemade in the best way. It has a tender banana cake base and a buttery cinnamon sugar streusel sprinkled generously over the top. If you have ripe bananas sitting on the counter and want something different from classic banana bread, this banana crumb cake recipe is a delicious way to use them.

This cake is full of comforting flavor. The sweetness of ripe bananas blends beautifully with softened butter, brown sugar, vanilla, and cinnamon. The crumb topping adds texture and a lightly spiced finish, making every slice soft in the middle with a sweet, crumbly top.

Banana crumb cake is perfect for breakfast, dessert, or an afternoon snack. It is simple to prepare, bakes in a 9×9 pan, and is a great recipe to make when your bananas are covered in brown spots and ready for baking.

Ingredients Notes

The full recipe and ingredient amounts are included in the recipe card below. Here are the key ingredients that make this banana crumb cake soft, flavorful, and perfectly tender.

• All-purpose flour – This forms the structure of the cake and is also used in the streusel topping.
• Bananas – Use very ripe bananas for the best flavor. You will need about 1 1/4 cups mashed banana, which is about 3 medium bananas or 2 large bananas. If using frozen bananas, thaw them first and drain off any extra liquid.
• Brown sugar – Dark brown sugar adds a deeper flavor, but light brown sugar also works well.
• Butter – Softened butter is used in both the cake and the streusel. Do not melt the butter for the crumb topping.
• Cornstarch – A small amount helps improve the texture of the cake.
• Cinnamon – Cinnamon adds warmth and pairs perfectly with the banana flavor.
• Eggs – Use room temperature eggs so they mix smoothly into the batter.
• Sour cream – Full-fat sour cream keeps the banana cake moist, soft, and fluffy.

Step by Step Instructions

Here is how to make and bake this easy banana crumb cake. You will need a 9×9 baking pan, parchment paper, mixing bowls, a spatula, and an electric hand mixer.

Step 1 – Prepare the pan. Preheat the oven to 350°F/176°C. Line the bottom and two sides of a 9×9 baking pan with parchment paper so the cake is easy to remove. Lightly grease the remaining sides. Mash the bananas and set them aside.

Step 2 – Make the streusel. In a medium bowl, combine the flour, brown sugar, white sugar, cinnamon, and softened butter. Mix with a fork or your hands until combined. Sprinkle in 1 tablespoon of extra flour and crumble the mixture into both small and larger pieces. Depending on how soft the butter is, you may need 1 more tablespoon of flour. Place the streusel in the fridge while you make the cake batter.

Step 3 – Mix the dry ingredients. In another medium bowl, stir together the all-purpose flour, cinnamon, cornstarch, baking soda, and salt. Set aside.

Step 4 – Cream the butter and sugars. In a large bowl, beat the softened butter, brown sugar, and white sugar on medium speed for 2 to 3 minutes, until light and fluffy. Scrape down the sides of the bowl as needed.

Step 5 – Add the eggs and vanilla. Add the eggs and vanilla to the butter mixture. Mix on medium speed until fully combined, scraping the sides of the bowl when needed.

Step 6 – Add the bananas. Mix in the mashed bananas until the batter is smooth and well combined.

Step 7 – Add the dry ingredients and sour cream. Add the dry ingredients in three additions, alternating with the sour cream. Begin and end with the dry ingredients. Mix only until just combined after each addition to keep the cake soft and tender.

Step 8 – Fill the pan. Spoon the batter into the prepared baking pan and spread it evenly. Sprinkle the chilled cinnamon streusel over the top of the batter.

Step 9 – Bake. Bake for 45 to 60 minutes, or until a toothpick inserted into the center comes out dry. The original bake time was 55 minutes.

Expert Baking Tips

These simple tips will help you get the best texture and flavor from your banana crumb cake.

• Use room temperature wet ingredients. Room temperature eggs and sour cream mix more evenly into the batter and help create a better texture.
• Use full-fat sour cream. Full-fat sour cream gives the cake a soft, rich crumb.
• Do not melt the streusel butter. The butter should be softened. Melted butter will change the texture of the crumb topping.
• Use very ripe bananas. Bananas with plenty of dark spots give the cake the best sweetness and banana flavor.
• Do not overmix the batter. Once the flour is added, mix only until the ingredients are combined.

FAQ

How do I store banana crumb cake?

This banana crumb cake is best served fresh or the next day. It can be kept on the counter for up to 2 days. For longer storage, place it in an airtight container and keep it in the fridge for up to 1 week.

Why is sour cream used in this cake?

Sour cream helps create a soft, fluffy cake texture and keeps the crumb moist. You cannot taste the sour cream in the finished cake. If you do not have sour cream, full-fat plain yogurt can be used instead.

Can I use frozen bananas?

Yes. Thaw frozen bananas completely and drain away any excess liquid before adding them to the batter.