Divide the **ground beef** into four equal portions, about 6 ounces each.
Gently shape each portion into a patty about 3/4 inch thick, taking care not to pack the meat too tightly.
Use your thumb to press a small **dimple** into the center of each patty to keep them flat during cooking.
Heat a **cast-iron skillet** or heavy pan over medium-high heat until it is shimmering and very hot.
Season both sides of each patty liberally with **kosher salt** and black pepper just before placing them in the pan.
Cook the patties for about **4 minutes** without moving them to develop a deep, dark brown crust.⏱ 4 min
Flip the patties and cook for another **3 to 4 minutes** for medium-rare, or until they reach your preferred doneness.⏱ 4 min
While the burgers cook, spread **softened butter** on the cut sides of the buns.
Toast the buns in a separate pan over medium heat until they are golden brown and crisp.
Let the burgers **rest for 2 minutes** on a plate before placing them on the toasted buns to serve.⏱ 2 min