PREHEAT oven to 350°F. Pierce potatoes with fork. Bake 1 hour. Let stand 5 min. Cut potatoes in half crosswise; scoop out centres, leaving 1/8-inch-thick shells.
PLACE potatoed in large bowl. Add butter and milk; beat with electric mixer on medium speed until fluffy. (If potatoes are dry, beat in small amount of additional milk). Spoon evenly into shells; lightly press 1 cheese cube in centre of each potato. Place potatoes in muffin pan.
BAKE 30 min. or until heated through. Sprinkle each with 1/2 tsp. bacon bits. Top with broccoli.