Pace 2 sliced of bread, butter side down in skillet or griddle. Layer with mozzarella, bacon, avocado, tomato and basil. Top with remaining slices of buttered bread (butter side up).
Heat over medium high heat and top sandwiches with the remaining slices of bread, butter-side-up and cook until golden and cheese begins to melt – about 4 minutes (you can cover with a lid to speed up the melting process.)
Carefully flip sandwich, reduce heat to medium and cook a few more minutes until cheese has melted and bread is golden brown.