Grilled Steak Burgers

For the burgers: Melt butter in 8-inch skillet over medium-low heat. Add garlic, onion powder, pepper, and salt and cook until fragrant, about 1 minute. Pour all but 1 tablespoon butter mixture into bowl and let cool slightly, about 5 minutes.

For the steak sauce: Meanwhile, add tomato paste to skillet and cook over medium heat until paste begins to darken, 1 to 2 minutes. Stir in broth, raisins, soy sauce, mustard, vinegar, and Worcestershire and simmer until raisins plump, about 5 minutes. Process sauce in blender until smooth, about 30 seconds; transfer to bowl.

Add 5 tablespoons cooled butter mixture and soy sauce to ground beef and gently knead until well combined. Shape into four ¾-inch-thick patties and press shallow divot in center of each. Brush each patty all over with 1 tablespoon steak sauce. Combine remaining 2 tablespoons cooled butter mixture with 2 tablespoons steak sauce; set aside.

For a charcoal grill: Open bottom vent completely. Light large chimney starter filled with charcoal briquettes (6 quarts). When top coals are partially covered with ash, pour evenly over grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.

For a gas grill: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Leave burners on high.

Clean and oil cooking grate. Grill burgers (covered if using gas) until meat registers 120 to 125 degrees (for medium-rare), 3 to 4 minutes per side, or 130 to 135 degrees (for medium), 4 to 5 minutes per side. Transfer burgers to plate, tent loosely with aluminum foil, and let rest 5 to 10 minutes. Brush cut side of buns with butter–steak sauce mixture. Grill buns, cut side down, until golden, 2 to 3 minutes. Place burgers on buns. Serve with remaining steak sauce.