Recipe Blueberry Breakfast Cake

Ingredients
2 cups all-purpose flour
1/2 cup sugar
2 teaspoons baking powder
1 egg, lightly beaten
1/2 cup milk
1/4 cup butter or margarine, softened
1 teaspoon grated lemon peel
2 cups fresh or frozen blueberries
TOPPING:
1/3 cup sugar
1/4 cup all-purpose flour
1/4 cup finely chopped walnuts
1/2 teaspoon ground cinnamon
3 tablespoons cold butter or margarine

Directions
In a mixing bowl, combine flour, sugar and baking powder. Add egg, milk, butter and lemon peel; mix just until dry ingredients are moistened. Fold in the blueberries. Spread in a greased 9-in. square baking pan. For topping, combine sugar, flour, walnuts and cinnamon. Cut in butter until mixture is crumbly. Sprinkle over batter. Bake at 350 degrees F for 40-45 minutes or until cake tests done.