01 -
Arrange the bacon strips in a cold skillet. Set over medium heat and cook until fully crisp, turning as needed for even browning, about 10 minutes. Transfer to a paper towel-lined plate to drain. Once cool, break bacon into halves or thirds to fit the sandwich.
02 -
Place the sourdough slices on a flat surface. Spread softened butter evenly over one side of each slice. If desired, spread a thin layer of Dijon mustard on the unbuttered side.
03 -
On two unbuttered bread surfaces, distribute half the shredded cheddar and mozzarella. Arrange half the crispy bacon strips and layer with dill pickle slices, using quantity according to preference. Season with a pinch of garlic powder and freshly ground black pepper, then top with the remaining cheese. Cap each with a second slice of bread, buttered side outward.
04 -
Heat a nonstick skillet or griddle over medium-low. Place the assembled sandwiches in the skillet and grill for 3 to 5 minutes or until the undersides are golden and crisp. Flip carefully and press gently with a spatula; grill an additional 3 to 4 minutes until the cheese is melted and both sides are golden.
05 -
Remove sandwiches from heat and allow to rest for 1 minute. Slice diagonally and serve immediately while the cheese is hot and gooey.