Blend the 1 cup flour and confectioners' sugar in a bowl.
Cut in the butter until blended.
Firmly and evenly press into an ungreased 9x9x2-inch baking pan.
Bake at 350Â°F about 15 minutes.
Meanwhile, combine sugar, 2 tablespoons flour, and baking powder; blend into beaten eggs along with the lemon juice.
Pour mixture over crust in pan.
Return to oven and bake 25 minutes.
Remove to wire rack to cool.
Spread with a thin confectioners' sugar icing and top with toasted sliced almonds.
Cut into bars.