1In 12-inch skillet, melt butter over medium heat. Add onion; sprinkle with salt and pepper. Cook onions about 5 minutes, stirring occasionally.
2Add bratwurst links; increase heat to medium-high. Cook about 8 minutes or until bratwurst are brown on all sides. Stir in apple cider and brown sugar. Heat to boiling. Reduce heat to medium; simmer about 5 minutes. Remove bratwurst from skillet; place on plate. Cover; set aside.
3Add apple to skillet; cook 10 minutes or until apple softens and sauce thickens. Return bratwurst to skillet. Serve.