This delightful coffee cake combines the sweetness of mixed berries with a buttery crumble topping, perfect for breakfast or a snack.
Preheat your oven to 375°F (190°C) and grease a 9-inch square baking pan.
Greasing the pan ensures the cake doesn't stick and comes out easily.
In a large bowl, combine the flour, granulated sugar, baking powder, and a pinch of salt.
Sifting the dry ingredients can help achieve a smoother batter.
In another bowl, whisk together the egg, melted butter, milk, and vanilla extract.
Ensure the butter is slightly cooled before mixing to prevent cooking the egg.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined.
Avoid overmixing to keep the cake tender.
Spread half of the batter into the prepared pan, then layer the mixed berries evenly on top.
Use fresh or thawed frozen berries for the best flavor.
Spoon the remaining batter over the berries, spreading gently to cover.
It's okay if some berries peek through the batter.
In a small bowl, mix the brown sugar, flour, cinnamon, and chopped walnuts. Cut in the cold butter until the mixture resembles coarse crumbs.
Use a fork or pastry cutter to blend the butter into the dry ingredients.
Sprinkle the crumble topping evenly over the batter in the pan.
Press the topping lightly to help it adhere to the batter.
Bake in the preheated oven for about 40 minutes, or until the topping is golden brown and a toothpick inserted into the center comes out clean.
Check the cake a few minutes before the timer ends to avoid overbaking.
Allow the cake to cool in the pan for 15 minutes before slicing and serving.
Serve warm for the best experience, optionally with a dollop of whipped cream.