Remove the lamb chops from the refrigerator 20 minutes before cooking to allow them to reach room temperature. Pat them very dry with paper towels.

In a small bowl, mix the ground coffee, chipotle powder, brown sugar, salt, and black pepper to create the rub.

Generously coat all sides of the lamb chops with the spice rub, pressing it gently into the meat.

Heat the olive oil in a heavy cast-iron skillet over medium-high heat until the oil is shimmering but not smoking.

Place the chops in the skillet and sear undisturbed for about 3-4 minutes until a dark crust forms.

Flip the chops. Immediately add the butter, smashed garlic, and rosemary sprigs to the pan.

Tilt the pan slightly and spoon the foaming butter over the chops repeatedly (basting) for another 2-3 minutes, or until the internal temperature reaches 130°F (54°C) for medium-rare.

Transfer the chops to a plate and pour the remaining pan juices over them. Let rest for 5 minutes before serving.