Cream together margarine and sugar. Add 4 eggs, one at a time, beating after each egg. Add 2 cups flour; mix well. Add 1 teaspoon vanilla. Put in greased 13 x 9-inch pan. Score 5 across and 8 down in batter. Put 1 cherry (from canned cherry pie filling) in each square. Bake at 350° for 30 minutes. Dust with confectioners' sugar.