Preheat your grill or stovetop grill pan over medium-high heat.
>brbr<
While the grill is heating, spread 1 teaspoon of soft butter on one side of each bread slice.
Place the bacon slices on the grill and cook until crispy, turning occasionally. This should take about 4-6 minutes. Remove the bacon from the grill and drain on paper towels.
Using the same grill or grill pan, toast the buttered side of the bread slices until golden brown. This should take about 1-2 minutes per side.
Once the bread is toasted, spread mayonnaise or your preferred sauce on the non-buttered side of each slice.
Assemble the sandwich by layering the green leaf lettuce, tomato slices, avocado slices, and bacon on one slice of bread. Season with salt and pepper to taste.
Top with the second slice of bread, mayo side down, to complete the sandwich.