Blackberry Breakfast Crumb Cake

By bakers_delight85

Ingredients

• For the crumb topping
• 1/3 cup all-purpose flour
• 3/4 cup packed light brown sugar
• 1 cup coarsely chopped walnuts
• 2 tsp. ground cinnamon
• 4 Tbsp. unsalted butter, melted
• For the Cake
• 1/2 cup (1 stick) unsalted butter
• 3/4 cup granulated sugar
• 1 large egg
• 1 cup plain lowfat yogurt
• 1 1/2 cups all-purpose flour
• 1/2 cup whole-wheat flour
• 1 tsp. baking soda
• 1 tsp. baking powder
• 1/2 tsp. salt
• 1 tsp. ground cinnamon
• 2 cups fresh blackberries

Preparation

Step 1

Place an oven rack in the center of the oven and preheat to 375 degrees F. Lightly butter a 9-inch square baking pan.
To make the crumb topping: In a small bowl, combine the flour, brown sugar, walnuts, cinnamon, and butter. Set aside.
To make the cake: In a large bowl, cream the butter and sugar until light and fluffy. Add the egg and yogurt and beat until well combined. In another bowl, stir the flours, baking soda, baking powder, salt, and cinnamon together and add to the butter mixture. Mix until just blended.
Spread the batter over the bottom of the pan. Sprinkle evenly with the blackberries and cover with the topping. Bake for 40 to 45 minutes, until the edges are light brown and toothpick inserted into the center of the cake comes out clean. Cool for 20 minutes before cutting.