Preheat oven to 350 degrees. Grease a 9-inch-square pan.
Mix first three ingredients together in a bowl and set aside. Toss blueberries with 2 tablespoons flour and set aside. In a bowl, cream butter and sugar; add eggs and beat well. Alternately add dry ingredients and milk to the mixture. Fold in blueberries. Pour into the prepared pan. Mix sugar and cinnamon together and sprinkle over the top of the cake. Bake 35 to 40 minutes.