Grind or finely chop 1 kg Angus beef. Season with salt and black pepper. Form into 4 equal patties, each slightly larger than the bun to account for shrinkage during cooking.
Slice the 2 onions, 2 tomatoes, and 4 pickled cucumbers into thin rings or slices. Arrange with iceberg lettuce leaves on a serving plate.
Heat a grill or pan to medium-high. Cook beef patties 3-4 min on the first side. Flip the patties, then immediately place 1 slice of cheddar cheese on each. Cook the second side until the internal temperature reaches 71°C (160°F), about 3-4 min more.
While the patties cook, toast the 4 hamburger buns in a toaster or on the grill until golden, 2-3 min. Fry the 8 bacon slices in a pan over medium-high heat until crispy, 5-7 min. Transfer bacon to a plate.
Place each cooked patty with melted cheese into a toasted bun. Add 2 bacon slices and sliced onions, tomatoes, pickles, and lettuce to each burger.
Serve burgers immediately while hot. Provide salt, pepper, mustard, ketchup, and mayonnaise on the side for guests to customize their burger.