Melt butter in oven in a 9 inch round cake pan.  Stir brown sugar into melted butter in pan.  Arrange peach slices over butter and brown sugar.  Whisk together the baking mix and white sugar in a mixing bowl.  Add buttermilk, egg and vanilla extract.  Stir well with a spoon.

Spread over the peach slices.  Bake in a preheated 350 degree oven for 50 to 55 minutes or until center tests done when stuck with a fork. Remove from oven and let sit for 10 minutes to cool before taking out of pan.  Makes 1 nine inch round cake.