In another bowl, stir together flour, baking powder, soda and salt. Add to the creamed mixture and mix on low speed or stir by hand just until blended. Spoon into a well greased 9 inch square pan. (I use a 9x13 pan.) Peel and slice peaches (or nectarines) 1/8 to 1/4 inch thick to make 2 cups fruit. Arrange evenly over batter, then sprinkle nut topping over all. Bake in a 350 degree oven for 45 to 50 minutes, or until a pick inserted in center (between fruit pieces) comes out clean. BAKING TIME IS LESS WHEN USING A 9X13 PAN.

Cool for 15 to 20 minutes, then serve warm. Or if made ahead, reheat in a 300 degree oven, uncovered, for about 10 minutes. It is also good cold. Makes about 9 servings.