Lay your four slices of bread on a cutting board. Spread the softened butter evenly on one side of each slice. This buttered side will be the outside of your sandwich, and it is what gives you that gorgeous, golden crust.

Flip two slices over so the buttered side faces down. Spread about a tablespoon of pizza sauce on each. Then add a generous layer of shredded mozzarella and cheddar. Arrange the pepperoni slices evenly over the cheese. If you are adding extras like mushrooms or jalapenos, scatter them on now. Sprinkle a tiny pinch of basil and garlic powder over everything. Top with the remaining two slices of bread, buttered side up.

Place a nonstick skillet or cast iron pan over medium low heat. Let it warm up for about a minute. You want a gentle heat so the bread toasts slowly and the cheese melts completely without burning the exterior.

Carefully place the assembled sandwiches into the skillet. Press down gently with a spatula. Let them cook for 3 to 4 minutes, or until the bottom is deep golden brown and crispy. Flip the sandwiches using a firm spatula. Cook the other side for another 3 to 4 minutes. The cheese should be oozing out the edges just a little, which is exactly what we want.

Transfer the sandwiches to a cutting board and let them rest for a minute. This helps the cheese set slightly so it does not all slide out when you cut. Slice in half with a sharp knife, revealing those beautiful, stretchy cheese pulls. Serve immediately with extra warm pizza sauce for dipping.