3/4 tsp. vanilla
1/2 c. butter
1 c. sugar
2 eggs
1/2 c. commercial sour cream
1/2 c. plain yogurt
1 c. unbleached flour
1 c. whole wheat flour
1 tsp. baking powder
1/2 tsp. baking soda
1/4 tsp. salt
3/4 c. blueberries

Cream butter and sugar. Add eggs and beat until smooth. Mix in sour cream, yogurt, and vanilla. Combine dry ingredients. Stir into creamed mixture. Fold in blueberries. Spoon into greased muffin pan, fill 1/2 full. Bake in preheated oven (400 degrees) for 25 to 30 minutes. Makes 2 dozen. Dust muffins with confectioners sugar when they are cooled, or just before serving if they are to be served warm.