**Banana Berry Crumble Cake**

**Ingredients:**

**For the Cake:**
– 1 1/2 cups all-purpose flour
– 1 teaspoon baking powder
– 1/2 teaspoon baking soda
– 1/4 teaspoon salt
– 1/2 cup unsalted butter, softened
– 3/4 cup granulated sugar
– 2 large eggs
– 1 teaspoon vanilla extract
– 1/2 cup sour cream or Greek yogurt
– 2 ripe bananas, mashed

**For the Crumble Topping:**
– 1/2 cup all-purpose flour
– 1/4 cup rolled oats
– 1/4 cup brown sugar
– 1/4 cup unsalted butter, cold and cubed
– 1/2 teaspoon ground cinnamon

**For the Topping:**
– 1 banana, sliced
– Fresh raspberries
– Fresh blackberries
– Powdered sugar for dusting

**Instructions:**

1. **Preheat the Oven:**
– Preheat your oven to 350°F (175°C). Grease and flour a 9-inch springform pan.

2. **Make the Cake Batter:**
– In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
– In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
– Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.
– Mix in the mashed bananas and sour cream until well combined.
– Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Be careful not to overmix.

3. **Prepare the Crumble Topping:**
– In a small bowl, combine the flour, oats, brown sugar, and cinnamon.
– Cut in the cold cubed butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.

4. **Assemble the Cake:**
– Pour the cake batter into the prepared springform pan and spread it evenly.
– Sprinkle the crumble topping evenly over the batter.

5. **Bake:**
– Bake in the preheated oven for 45-55 minutes, or until a toothpick inserted into the center comes out clean.
– Let the cake cool in the pan for 10 minutes before removing the sides of the springform pan. Allow the cake to cool completely on a wire rack.

6. **Add the Fruit Topping:**
– Once the cake is cooled, top it with sliced bananas, fresh raspberries, and blackberries.
– Dust the top with powdered sugar before serving.

7. **Serve:**
– Slice and enjoy this delicious banana berry crumble cake, perfect for dessert or a special breakfast treat.

This cake is a delightful combination of moist banana cake, a crunchy crumble topping, and fresh fruit, making it both beautiful and delicious. Enjoy!