Preheat the oven to 375°F.
Place bacon on a cooling rack and place the cooling rack on a sheet pan. Place in the oven, and bake until bacon is crispy, about 15-18 minutes. Remove the bacon from the oven and let cool, reserving 2 tablespoons of bacon grease for the Brussels sprouts. Once the bacon has cooled, chop into small ¼-inch sized pieces.
Increase the oven temperature to 400°F.
In a small bowl, whisk together reserved bacon grease, mustard, salt, pepper, and garlic powder. Toss together with Brussels sprouts and spread onto a foil-lined baking sheet.
Place the Brussels sprouts in the oven, and bake until browned and crisp-tender, about 12-15 minutes. Once removed from the oven, place the Brussels sprouts into a bowl and top with bacon. ENJOY!