Prep
0
min
Cook
40
min
Serves
4
people
Level
intermediate
📝 Ingredients
🥬Fresh Produce(1)
- 1 cup (240ml) mashed banana from about 2 medium ripe bananas
🥛Dairy & Eggs(5)
- ⅓ cup (80g) full fat sour cream, at room temperature
- 1 large egg, at room temperature
- 3 tablespoon (42g) salted butter, very soft
- 6 tablespoon (84g) unsalted butter, browned
- 1 tablespoon (15ml) whole milk
🫙Pantry Staples(10)
- ⅓ cup (50g) all-purpose flour
- 1 ¼ cups (180g) all-purpose flour
- ½ teaspoon baking powder
- ½ teaspoon baking soda
- 1 teaspoon cocoa powder
- ¼ cup (55g) packed light brown sugar
- 3 tablespoon (45g) packed light brown sugar
- ⅔ cup (145g) packed light brown sugar
- ½ cup (60g) powdered confectioner's sugar
- 1 teaspoon (5ml) pure vanilla extract
🧂Spices & Seasonings(4)
- 1 teaspoon cinnamon
- ½ teaspoon ground cinnamon
- ¼ teaspoon ground cinnamon
- ½ teaspoon salt
👨🍳 Instructions
- 1
Preheat your oven the 350 degrees F and line an 8x8-inch square baking pan with parchment paper, allowing the paper to hang over the sides about 2 inches for easy removal.
- 2
First brown the butter. Follow the instructions in this post here to learn how to brown butter. It's easy!
- 3
Make the streusel. Combine the flour, brown sugar and cinnamon in a bowl so it is evenly blended and there are no lumps of brown sugar. Add soft butter and rub it in evenly until it forms soft crumbs. Cover the bowl and set aside.
- 4
Make the cinnamon sugar mixture. Combine brown sugar, cinnamon and cocoa powder and set aside.
- 5
Make the banana batter. Combine flour, baking powder, baking soda, and salt in a medium bowl and whisk to blend evenly. Add mashed banana to a large mixing bowl and whisk in brown sugar until smooth and glossy. Add egg, sour cream, cooled browned butter and vanilla and whisk together until evenly combined. Add the dry ingredients and gently fold them in using a rubber spatula.
- 6
Spread two-thirds of the batter evenly into the pan. Sprinkle the cinnamon sugar evenly over top to cover it entirely. Dollop remaining batter on top and then gently spread it out evenly. It may be difficult to spread the thick batter over the dry sugar layer, so what works best is spread the batter dollops into each other first so they are touching (this helps build more tension), then continue to spread out to the sides and into the corners. Crumble the streusel on top in an even layer.
- 7
Bake for 35-40 minutes until a toothpick inserted into the center comes out clean. Transfer the pan to a wire rack and let cool completely.
- 8
Make the glaze. Whisk together the powdered sugar, milk and cinnamon in a small bowl. It should make a glue-like consistency. If it's too thick, add ½ teaspoon of milk at a time until it turns smooth. Drizzle the icing on top of the slightly warm cake and enjoy!
💡 Pro Tips
- ✓Brown butter to 320-325°F (when milk solids turn golden and smell nutty) then immediately transfer to a cool bowl to stop cooking, as residual heat can push it to bitter burnt territory within 30 seconds.technique320-325°F
- ✓Use bananas with 25% brown spots for optimal sweetness and moisture - they contain 25% more sugar than yellow bananas and break down easier for smoother batter integration.ingredient25% brown spots
- ✓Cool your browned butter to 80-85°F before adding to the wet ingredients to prevent the sour cream from curdling and the eggs from scrambling.timing80-85°F
- ✓Create streusel with a 3:1:1 ratio of flour to fat to sugar, then rub butter in until mixture feels like coarse breadcrumbs - this ensures distinct crumbly pieces rather than a paste.technique3:1:1 ratio
- ✓Test doneness at 35 minutes by inserting a toothpick 1 inch off-center rather than dead center, as the cinnamon sugar layer creates a moisture pocket that can give false readings in the exact middle.technique35 minutes
Share this recipe