2 1/2 cups (lightly packed) fresh basil leaves 1 cup mayonnaise 1/4 cup butter, at room temperature 12 slices thick-sliced bacon 12 slices (1/2-inch-thick size) fresh country-style white bread or sliced french bread or sour dough bread 3 large tomatoes, cut into 1/4-inch-thick rounds 2 ripe avocados, pitted, peeled, sliced 1 red onion, thinly sliced 6 lettuce leaves
Mix basil, mayonnaise and butter in processor until basil is finely chopped and mixture is well blended. Season to taste with salt and pepper. Can be made 1 day ahead. Cover and refrigerate.
Cook bacon in heavy large skillet over medium-high heat until crisp, about 8 minutes. Transfer to paper towels; drain.
Spread half of mayonnaise mixture over 1 side of half the bread slices. Top each with 2 tomato slices. Sprinkle tomatoes with salt and pepper. Top tomato slices with avocado, then with bacon strips, onion and lettuce. Spread remaining mayonnaise mixture over remaining bread slices. Place bread slices atop lettuce. Cut sandwiches in half and serve.
The basil-mayo-butter spread is worth dirtying the food processor for because you'll want to make it again to use on everything (including making this sandwich daily until you run out of bread). I think this really does qualify as the "best" BLT. Hope someone won a contest with it or something becuase it's amazing