PREHEAT oven to 375° F.
COMBINE flour, oats, sugars, baking powder and salt in large bowl. Cut in butter with pastry blender or two knives until mixture is crumbly. Reserve 1 cup oat mixture for streusel. Press remaining oat mixture onto bottom of ungreased 8-inch square baking pan.
BAKE for 10 minutes. Transfer to wire rack.
SPREAD preserves evenly over hot crust to within 1/2 inch of edges. Sprinkle evenly with 1 cup morsels. Combine reserved oat mixture and almonds, if desired; sprinkle over morsels, patting gently.
BAKE for 30 to 35 minutes or until golden brown. Cool completely in pan on wire rack. Drizzle with melted chocolate, if desired. Let chocolate set before cutting into squares. Store tightly covered.