01 -
Preheat a skillet over medium heat.
02 -
Mash the avocado with a sprinkle of salt and pepper until smooth.
03 -
In a bowl, combine shredded mozzarella and cheddar.
04 -
Spread butter on one side of each bread slice and coat the unbuttered sides of two slices with mayonnaise.
05 -
Place the mayonnaise-side slices (mayo down) in the skillet. Spread mashed avocado over each slice and sprinkle with garlic powder and onion powder.
06 -
Layer the cheese mixture over the avocado and top with fresh basil leaves, if desired.
07 -
Place the remaining bread slices on top, butter-side up.
08 -
Grill for 3-4 minutes per side until the bread is golden brown and the cheese is melted.
09 -
Slice the sandwiches and serve warm.