1/2 cup margarine
3/4 cup sugar plus another 1/4 cup sugar
4 medium eggs (3 large, 2 jumbo), separated
1 teaspoon vanilla
1 1/2 cups flour
1 1/2 teaspoons baking powder
1/3 cup milk
1 1/2 cups blueberries (fresh or frozen -- do not thaw first)
2 Tablespoons sugar mixed with 1 teaspoon cinnamon

Grease and flour a 9X9 inch square pan. Preheat oven to 350 degrees.

Sift together flour and baking powder and take 1/2 cup to shake through the blueberries until they are coated with flour (this helps keep them from sinking in the batter).

Use a wooden spoon to cream together the margarine and 3/4 cup sugar. Add the egg yolks and beat them in well, one by one. Add the vanilla.

Alternate adding flour and milk.

Beat the egg whites until fluffy. Add the reserved 1/4 cup sugar and beat until stiff peaks form. Fold whites gently into the batter. When they are about half mixed in, add the blueberries and fold until mixed. Pour into prepared pan and sprinkle with cinnamon sugar. Bake for about 50 minutes or until the cake springs back when touched or a toothpick comes out clean.