1 c. all-purpose flour
3/4 c. brown sugar, firmly packed
1/4 c. butter
1/2 c. sour cream
1 egg, beaten
3/4 tsp. baking powder
1/4 tsp. salt
1 tsp. cinnamon
1/2 tsp. vanilla extract
1 c. fresh blackberries
Sifted powdered sugar

Combine flour and brown sugar. Cut butter in with pastry cutter until mixture resembles coarse meal. Press mixture into bottom of an 8-inch square pan.

Combine baking powder, sour cream, eggs, salt, vanilla, and cinnamon. Blend well. Spoon in blackberries and stir gently. Spoon over crust.

Bake at 350°F for 35 minutes. Sprinkle with powdered sugar. Cut into bars.