Preheat the grill to medium-high heat and oil the grate. Butter each hamburger bun half.
STEP 2
Cook bacon in a skillet over medium-high heat until crisp, about 10 to 12 minutes. Drain on paper towels. Set skillet aside.
STEP 3
In a bowl, combine ground beef, Worcestershire sauce, and steak seasoning. Form into 4 patties and make a thumbprint in the center of each.
STEP 4
Grill patties until desired doneness, about 6 minutes per side. Use a thermometer to check for 160°F (71°C).
STEP 5
Top each burger with 2 strips of bacon and 1 slice of Cheddar cheese. Close the grill lid until melted, about 1 minute.
STEP 6
Toast the buns on the grill, buttered-sides down, until browned, about 1 minute.
STEP 7
Reheat bacon grease, crack eggs into skillet, and cook until whites are set but yolk is runny, about 4 minutes. Place 1 egg on each patty. Top with lettuce, onion, avocado, and top buns.