In medium bowl, stir together flour, baking powder, cinnamon and salt, if desired. Stir in fruit, oatmeal and peanuts. Set aside. In large bowl, beat together eggs, sugar, peanut butter and vanilla until smooth. Stir in reserved flour mixture. Pour into greased 11x7x1 1/2-inch baking pan. Bake in preheated 350° oven until cake tester inserted in center comes out clean, about 20 to 25 minutes. Cut into 12 bars. Remove from pan. Cool on wire rack.