Razzy-Apple Streusel Bars

Heat oven to 375°F (190°C). In large bowl, combine 2 1/2 cups flour, oats, sugar and baking powder; mix well. Add butter, mixing until moistened. Reserve 2 cups oat mixture for topping. Press remaining oat mixture evenly onto bottom of ungreased 13 x 9-inch baking pan. Bake 15 minutes. Cool slightly on wire rack. In medium bowl, stir together apples and 2 tablespoons flour. Add preserves; stir until apples are evenly coated. Spread onto crust to within 1/2-inch of edges. Sprinkle with reserved oat mixture, patting gently. Bake 30 to 35 minutes or until light golden brown. Cool completely in pan on wire rack. Cut into bars. Store tightly covered.