Make the herb butter first so it has time to develop flavor. In a small bowl, combine the softened unsalted butter with the minced garlic, chopped parsley, thyme, minced rosemary, lemon zest, lemon juice, and red pepper flakes if using. Mix everything together with a fork until fully combined and the herbs are evenly distributed throughout the butter. Taste it - it should be bright, garlicky, and herbaceous. Roll it into a log using plastic wrap or keep it in the bowl and refrigerate it while you prep the quail. Pulling it out 10 minutes before you need it will bring it back to a spreadable consistency.

Butterfly each quail by placing the bird breast-side down on a cutting board. Using kitchen shears, cut along both sides of the backbone from tail to neck and remove it entirely. Flip the bird breast-side up and press down firmly on the breastbone with the heel of your hand until you feel it crack and the bird flattens out. This spatchcock cut is critical - it gives you maximum surface area on the grill grates, promotes even cooking on both sides, and dramatically reduces your cook time. If your quail came pre-butterflied from the butcher, you are already ahead of the game.

Pat each butterflied quail completely dry with paper towels - and we mean completely dry. Moisture is the enemy of crispy skin. Any surface moisture will steam the skin rather than crisp it, and on a small bird like quail, you do not have a second chance. Once dry, drizzle olive oil over both sides of each bird and rub it in evenly. This oil serves as the adhesive for your seasoning and helps promote that golden crackling skin over direct heat.

Mix together your dry rub: kosher salt, black pepper, garlic powder, smoked paprika, onion powder, and cayenne if using. Season every bird generously on both sides, pressing the rub gently into the skin and meat. Do not be shy here - quail are small and the seasoning needs to work fast. Let the seasoned birds rest at room temperature for 20 to 30 minutes while you build your fire. This rest period lets the salt begin to work into the surface of the meat and takes the chill off the birds for more even cooking.

Fire up the grill. For charcoal, light a full chimney of hardwood lump charcoal and let it burn until the coals are glowing orange and covered in a thin layer of white ash - this takes about 15 to 20 minutes. Set up a two-zone fire by banking all the coals to one side of the grill. This gives you a direct high-heat zone for searing the skin and an indirect zone where you can move birds if they are cooking too fast. Your direct heat zone should be ripping hot - we are talking 450 to 500 degrees Fahrenheit at grate level. Clean the grates with a wire brush and oil them lightly with a folded paper towel dipped in vegetable oil, using your long tongs to apply it.

Place the quail breast-side down over direct heat first. This is where the magic happens - you want to hear that aggressive sizzle the second the birds hit the grates. Grill breast-side down for 5 to 6 minutes without moving them. Resist the urge to lift and peek constantly. Let the grill do its work. You are building color, crisping that skin, and developing beautiful char marks. After 5 to 6 minutes, check the underside - you want deep golden-brown color with distinct grill marks, not black char.

Flip each quail using your long tongs and cook bone-side down for another 5 to 7 minutes over direct heat. At this point, start checking your internal temp. Insert your instant read thermometer into the thickest part of the breast, avoiding the bone. You are targeting 165 degrees Fahrenheit. If birds are browning too aggressively before reaching temp, slide them over to the indirect zone to finish cooking with the lid closed. The indirect side acts like a convection oven and gently brings the internal temp up without burning the outside.

While the quail finish cooking, place your cast iron skillet directly on the grill grates over medium heat on the indirect side. Add the herb butter to the skillet and let it melt slowly, swirling occasionally. You will see it foam slightly and then settle into a gorgeous pool of green-flecked golden butter. Do not let it brown or burn - you want it melted and warm, not clarified. This takes about 2 to 3 minutes on the grill.

Once your quail hit 165 degrees Fahrenheit, pull them off the grill immediately and place them directly into the cast iron skillet with the herb butter. Spoon the butter over the birds generously, turning them so every surface gets coated. Let the residual heat of the skillet and butter do the final work. This is your basting moment - do it enthusiastically and do not rush it. Every spoonful of butter adds richness, moisture, and flavor back into those small birds.

Rest the meat for 3 to 5 minutes before serving. Even on a small bird like quail, resting allows the juices to redistribute throughout the meat so they stay in the bird when you cut in rather than running out onto the cutting board. Transfer the quail to a serving platter, pour any remaining herb butter from the skillet directly over the top, garnish with fresh rosemary sprigs and lemon wedges, and bring it to the table while everything is still steaming hot. Serve two quail per person as a main course alongside grilled vegetables or a simple salad.