Preheat an individual sandwich maker or see below for skillet instructions. Place one cheese slice on one bread slice.

Spread avocado slices over the cheese slice leaving a small border of cheese around the edges. (Tip, if using a sandwich maker, place the avocado slices to either side of the sandwich maker’s diagonal bar.)

Top with the second slice of cheese, the bacon slices and the remaining bread slice.

Combine the melted butter and mayonnaise; spread half the mixture onto the top slice of bread.

Carefully place the sandwich into the sandwich maker with the butter-mayonnaise spread side down.

Spread the remaining butter-mayonnaise mixture on the other side of the sandwich and close the sandwich maker. Cook for 2 to 5 minutes or until the sandwich is golden brown and the cheese is melted. With a heat resistant spatula or tongs remove cooked sandwich and place on a plate. Cut in half and serve immediately.

Preheat skillet over medium-high heat. Place sandwich in skillet, spread butter mayo mixture on second side of bread and cook for 3 minutes. Carefully flip the sandwich. If you have a grill press, place that on top of the sandwich to weigh it down, otherwise gently press on the sandwich using a heat resistant spatula. Cook for 2 minutes more or until the sandwich is golden brown and the cheese is melted. If the bread seems too dry spread with a little extra butter and cook for a few seconds more on both sides.