Blackberry Coffee Cake with Streusel Topping

Preheat oven to 350 °F. Butter an 8-inch square pan; set aside.

For the topping, in a large bowl, stir together 1/3 cup flour, 1/4 cup granulated sugar, brown sugar and cinnamon. Using a pastry cutter or your finger, cut in 1/4 cup butter until the mixture resembles coarse crumbs. Refrigerate until ready to use.

For the cake; in a medium bowl, whisk together 1 cup flour, baking powder, ginger and salt. In a large mixing bowl, cream the remaining 1/4 cup butter with an electric mixer on medium speed. Add the remaining 1/2 cup sugar; beat until light and fluffy. Beat in the egg and vanilla. Alternately beat in the flour mixture and the milk until just combined.

Spread the batter evenly in the prepared pan. Scatter the blackberries over the batter. Sprinkle with the streusel topping. Bake for 45 to 60 minutes or until a toothpick inserted in the center of the cake comes out clean. Transfer to wire rack to cool slightly before serving.