Bring tomahawk steaks to room temperature, season with salt, pepper, and garlic powder; let sit for 45 minutes.
Coat bacon with brown sugar, bake at 400°F on a wire rack for 20 minutes; let cool, then chop.
Mix butter with chopped candied bacon, garlic paste, vinegar, red pepper flakes, salt, and black pepper; roll into a log and refrigerate for 45 minutes.
Oven-roast steaks low and slow, then sear in a hot skillet.
Top each steak with bacon butter, cover with foil, and let rest for 10-12 minutes.