01 - Place bacon slices in a skillet over medium heat and cook until crisp. Transfer to paper towels to drain excess fat.
02 - Combine ricotta cheese with chopped chives and freshly ground black pepper in a small mixing bowl.
03 - Arrange the four slices of bread; evenly spread softened butter on one side of each slice.
04 - On the unbuttered sides of two slices, evenly spread half the ricotta mixture per slice. Top each with half the shredded mozzarella and two bacon strips. Close with the remaining bread, keeping the buttered sides facing outward.
05 - Heat a nonstick skillet over medium heat. Place the prepared sandwiches in the skillet and grill for 3 to 4 minutes per side, pressing gently, until the bread is golden brown and cheese is melted.
06 - Transfer sandwiches to a cutting board, slice each in half, and serve immediately.