Mickey Mazur's Blueberry Coffeecake

Ingredients:
2 cups flour
3/4 cup sugar
2 1/2 teaspoons baking powder
1/4 teaspoon salt
1/4 cup butter
1/4 cup milk
1/2 cup sour cream
1 egg
2 cups blueberries

Topping:
1/2 cup sugar
1/3 cup flour
1 teaspoon cinnamon
1/4 cup butter, melted

Icing:
1/2 cup powdered sugar
Water

Instructions:Preheat oven to 375 degrees. Grease 9-inch spring-form pan with 3-inch sides.In a large bowl, blend together flour, sugar, baking powder, and salt. Cut in butter. Add milk, sour cream, and egg. Beat with spoon 30 seconds and fold in blueberries. Spread batter carefully in pan.Combine sugar, flour, cinnamon, and butter to topping and sprinkle over batter. Bake 45-50 minutes. Combine powdered sugar and enough water for icing with a drizzling consistency. Drizzle over cake while cake is still warm.