• 1 ½ teaspoons baking powder
• 1 pint blueberries (reserve about 6 berries)
• ¼ cup butter, softened
• ½ teaspoon vanilla extract or butter vanilla bakery emulsion
• ¼ teaspoon cream of tartar
• 1 egg, separated
• 1 cup sifted flour
• 1/3 cup milk
• ¼ teaspoon salt
• ½ cup sugar

Preheat oven to 375 degrees.Wash blueberries and pat dry.Spray six 6-ounce custard cups with baking spray.Divide blueberries among custard cups, reserving 6 to top cakes.Combine flour, salt and baking powder in a mixing bowl and set aside.Beat egg white until foamy; add cream of tartar and beat until stiff peaks form. Set egg white aside.Cream butter; gradually add sugar and continue creaming until light.Add eggs and vanilla; mix until well blended.Add flour mixture, alternating with milk, to butter mixture and beat until well combined. Batter will be thick.Gently fold beaten egg white into flour/butter mixture.Spoon batter into custard cups over berries, filling no more than full.Place custard cups on a baking sheet; bake for 30 minutes or until cakes test done by inserting a toothpick near center.Turn out cakes directly from oven on wire racks.Serve warm or at room temperature. If desired, serve with whipped cream or ice cream topped with a blueberry.