Combine brown sugar, butter and corn syrup in a small saucepan; cook over low heat until thick. Pour into an ungreased 13"x9" baking pan, arranging apple slices on top of syrup. Beat eggs, milk and vanilla in a mixing bowl. Dip French bread in egg mixture and arrange over apple slices. Cover and refrigerate overnight. Remove from refrigerator 30 minutes before baking, and uncover. Bake at 350 degrees for 35 to 40 minutes, until the top of the bread is browned. Meanwhile, combine remaining ingredients in a saucepan and cook over medium heat until jelly is melted. Serve French toast with apple slices on top and spoon the warm sauce over the apples.