Turn up the fun at your next get-together with our amazing Mini Cheeseburger Cups. An easy-to-make variation on traditional sliders, Mini Cheeseburger Cups have all the great flavors you'd expect: onions, ketchup, mustard, KRAFT Singles and relish.
1 lb. lean ground beef
1 cup chopped onions
3/4 cup HEINZ Tomato Ketchup, divided
3 Tbsp. HEINZ Yellow Mustard, divided
8 KRAFT Singles, divided
1 pkg. (12 oz.) Hawaiian sweet rolls
3 Tbsp. HEINZ Sweet Relish