In a small saucepan, cook brown sugar, butter and syrup until thick, about 5 to 7 minutes. Pour into an ungreased 9 x 13 pan; arrange apples on top. In a mixing bowl, beat eggs, milk and vanilla. Dip bread slices into the egg mixture for 1 minute; place over apples. Cover and refrigerate overnight. Remove from the refrigerator 30 minutes before baking. Bake, uncovered at 350 for 35 to 40 minutes. Combine syrup ingredients in a medium saucepan; cook and stir until hot. Serve over French toast.