Combine first 9 ingredients and red pepper, if desired. Spoon into a lightly greased 11- x 7-inch baking dish.
Bake at 350° for 30 minutes or until hot and bubbly. Stir together breadcrumbs and melted butter; sprinkle over casserole, and bake 10 more minutes. Let casserole stand 5 minutes before serving.
Note: Freeze unbaked casserole, omitting breadcrumbs and butter, for up to 1 month, if desired. Allow to stand at room temperature 1 hour. Bake at 350° for 1 hour and 30 minutes or until hot and bubbly. Stir together breadcrumbs and melted butter; sprinkle over casserole, and bake 10 more minutes. Let stand 5 minutes before serving.
