Prepare the Garlic Basil Mayo:

1. In a small bowl, combine ¼ cup mayonnaise, 2 tablespoons fresh chopped basil, 1 minced garlic clove, and the zest of 1 lemon.
2. Mix well until smooth and creamy. Set aside for sandwich assembly.

Toast the Bread:

1. Lightly toast all 9 slices of bread to give them a golden crisp, which will provide a sturdy base for the layers of ingredients.

Assemble the First Layer:

1. Lay out 3 slices of toast and spread a thin layer of mayonnaise on one side of each slice.
2. On the first slice, layer a piece of green leaf lettuce, followed by a couple of slices of the hothouse tomato.
3. Add a layer of the deli ham, thinly shaved, followed by a few slices of smoked cheddar cheese.

Assemble the Second Layer:

1. Place the second slice of toasted bread on top of the ham and cheddar layer, spread some garlic basil mayo on the top side.
2. Add thinly sliced Granny Smith apple, avocado slices, and a generous amount of roasted turkey deli meat.
3. Top with a couple of crispy slices of Applewood smoked bacon.

Finish the Third Layer:

1. Place the final slice of toast on top of the sandwich stack, pressing down slightly to hold everything together.
2. Secure each sandwich with long toothpicks or sandwich skewers if needed to prevent it from falling apart.

Slice and Serve:

1. Slice the sandwich diagonally into halves or quarters, depending on how you prefer to serve it.
2. Serve immediately with chips, a side salad, or pickles for a complete meal.