01 -
Arrange bacon strips in a cold skillet and cook over medium heat, turning occasionally, until crisp. Transfer to a paper towel-lined plate.
02 -
Evenly spread softened butter on one side of each bread slice. Spread mayonnaise on the opposite side of each slice.
03 -
Place four bread slices, butter-side down, on a work surface. Layer with sharp cheddar, mozzarella, and provolone cheeses. Add two bacon strips per sandwich and sprinkle with a bit more cheese. Top with remaining bread slices, butter-side up.
04 -
Heat a large skillet over medium-low heat. Add assembled sandwiches and cook for 3 to 4 minutes per side, pressing gently, until the bread is golden brown and cheese fully melted.
05 -
Transfer sandwiches to a cutting board, slice in half, and serve immediately while hot.