PREHEAT oven to 350°F. Line a 13- x 9- x 2-inch baking pan with Reynolds Parchment Paper, extending paper up sides of pan; set aside. COMBINE crust ingredients in a large bowl on low speed of an electric mixer until mixture is crumbly. Press mixture evenly into parchment-lined pan.
BAKE 20 minutes or until light brown; remove from oven.
BEAT together filling ingredients in a medium bowl until well blended; pour mixture evenly over warm baked crust.
RETURN to oven and CONTINUE BAKING 15 to 20 minutes longer or until filling is set and bars are brown around the edges. Cool completely on a wire rack. Use edges of parchment lining to lift bars from pan. Place on a cutting board. Pull back edges of parchment for easy cutting; sprinkle with additional powdered sugar. Cut into bars.
REYNOLDS KITCHENS TIP: Cut out decorative stencils using Reynolds Parchment Paper. Just before serving, arrange stencils over surface of lemon bars. Sprinkle powdered sugar over stencils. Remove stencils.