Melt In Your Mouth Blueberry Cake

1/2 cup butter
3/4 cup (divided) white sugar
1 tablespoon white sugar
1/4 teaspoon salt
1 teaspoon vanilla extract
1 egg yolks
1 egg whites
1 1/2 cups all-purpose flour
1 tablespoon all-purpose flour
1 teaspoon baking powder
1/3 cup milk
1 1/2 cups fresh blueberries

Preheat oven to 350 degrees F (175 degrees C). Grease and flour an 8 inch square pan.
Cream butter or margarine and 1/2 cup sugar until fluffy. Add salt and vanilla. Separate eggs and reserve the whites. Add egg yolks to the sugar mixture; beat until creamy.
Combine 1 1/2 cups flour and baking powder; add alternately with milk to egg yolk mixture. Coat berries with 1 tablespoon flour and add to batter.
In a separate bowl, beat whites until soft peaks form. Add 1/4 cup of sugar, 1 tablespoon at a time, and beat until stiff peaks form. Fold egg whites into batter. Pour into prepared pan. Sprinkle top with remaining 1 tablespoon sugar.
Bake for 50 minutes, or until cake tests done.