Begin by spreading about 1/2 tablespoon of softened butter evenly on one side of each slice of sourdough bread, ensuring comprehensive coverage for a beautifully golden crust.
On the unbuttered side of two slices, generously spread 2 tablespoons of basil pesto, covering the entire surface.
Arrange 2 slices of fresh mozzarella cheese atop the pesto-covered bread, ensuring even distribution for perfect meltiness.
Sprinkle 1 tablespoon of grated Parmesan cheese over the mozzarella layer. For an extra crunch and freshness, feel free to add a handful of arugula or spinach on top of the cheese.
Top with the remaining slices of bread, ensuring the buttered sides are facing outward, forming a delicious sandwich.
Preheat a skillet over medium heat. Once hot, carefully place the prepared sandwiches in the skillet, allowing them to sizzle.
Cook for approximately 3-4 minutes on one side, watching for a rich golden brown color. Use a spatula to gently flip the sandwiches.
After flipping, sprinkle a pinch of garlic powder over the newly exposed side. Cook for an additional 3-4 minutes, or until the second side achieves a golden hue and the cheeses have melted into a gooey delight.
Once cooked to perfection, remove the sandwiches from the skillet and allow them to rest for a minute. This step is essential for preventing a cheesy explosion when sliced!
Serve warm, with a light sprinkling of salt and pepper to enhance all the flavors of this delightful dish.
Notes
For an appealing presentation, cut the sandwiches diagonally and serve with a side of marinara sauce for dipping.