01 -
Heat a large skillet over medium heat until hot enough to toast bread evenly.
02 -
In a small bowl, mash avocado with a fork until smooth. Season with salt and pepper according to preference.
03 -
Mix shredded mozzarella and cheddar cheese together in a separate bowl for even distribution.
04 -
Spread softened butter evenly on one side of each bread slice. Spread a thin layer of mayonnaise on the unbuttered side of two slices.
05 -
Place the two slices of bread, mayonnaise side down, into the skillet. Evenly spread the mashed avocado over each slice in the skillet. Sprinkle garlic powder and onion powder over the avocado.
06 -
Distribute the cheese mixture evenly on top of the avocado layer. If desired, add fresh basil leaves.
07 -
Top each with the remaining bread slices, ensuring the buttered sides face upward.
08 -
Cook sandwiches for 3–4 minutes per side, pressing gently, until bread is golden brown and cheese is thoroughly melted. Adjust heat as needed to prevent burning.
09 -
Remove sandwiches from skillet and allow to cool slightly before slicing. Serve warm.