1.Preheat oven to 400°.
Cook bacon in a medium nonstick skillet over medium heat until crisp. Remove from skillet; crumble and set aside. Wipe skillet clean with paper towels.
Place skillet coated with cooking spray over medium heat until hot. Add garlic; sauté 1 minute. Set aside.
Bake potatoes at 400° for 1 hour or until done; cool slightly. Cut a lengthwise slit across top of potatoes; carefully scoop pulp into a bowl, leaving shells intact. Add half of crumbled bacon, garlic, sour cream, 1/4 cup cheese, 3 tablespoons onions, milk, and salt to pulp; mash.
Increase oven temperature to 450°. Stuff shells with potato mixture; top with half of crumbled bacon, 1/4 cup cheese, and remaining onions. Place the stuffed potatoes on a baking sheet. Bake at 450° for 15 minutes or until potatoes are thoroughly heated. Sprinkle with pepper, if desired.