Blueberry Coffee Cake

Preheat oven to 350ºF. Grease a 13 by 9 inch metal baking pan; dust pan with flour or use baking spray that has flour in it such as Baker’s Joy.

Prepare streusel topping: In a medium bowl, combine brown sugar, 1/2 cup flour, and cold butter. With your fingertips, work in butter until mixture is crumbly. Refrigerate streusel while preparing cake.

Prepare the coffee cake: On waxed paper or flexible mat, combine the remaining 2 1/2 cups flour, baking powder, baking soda, and salt. In a large bowl with the mixer at low speed, beat the granulated sugar with the softened butter until blended. Increase speed to medium-high and beat until creamy, about 2 minutes, frequently scraping the sides of the bowl with a rubber spatula. Reduce speed to low; add eggs, 1 at a time, beating well after each addition. Beat in vanilla.

At low speed, beat in flour mixture alternately with buttermilk, beginning and ending with the flour mixture. Beat just until batter is smooth, occasionally scraping the bowl with a rubber spatula. With a spatula, fold in all but 1/2 cup blueberries.

Spoon batter into prepared pan; spread evenly. Sprinkle batter with reserved blueberries. With fingers, press streusel into clumps and sprinkle evenly over the batter. Bake coffee cake 35 to 40 minutes or until a toothpick inserted in the center comes out clean. Cool cake in the pan on a wire rack 1 hour to serve warm, or cool completely to serve later.