Line a 13- x 9-inch pan with aluminum foil, allowing extra to hang over the sides; set aside.
Combine flour and 1/2 cup powdered sugar. Cut butter into flour mixture with a pastry blender until crumbly; stir in almonds. Firmly press mixture into prepared pan.
Bake at 350° for 20 to 25 minutes or until light golden brown.
Stir together Lemon Chess Pie Filling and coconut; pour over baked crust.
Bake at 350° for 30 to 35 mintues or until set. Cool in pan on a wire rack. Sprinkle evenly with remaining 1/2 cup powdered sugar; lift tart out, and slide it onto a serving platter. Garnish, if desired.