In a large saucepan filled with 1/2 gallon of water, bring water to a simmer. Add all Brine ingredients and stir. Allow to come to a boil, then cool broth. Add turkey and place in refrigerator for 2 to 4 hours.
Place bacon strips onto cookie sheet. Place in oven for 12 to 14 minutes. Remove from the oven and drain on paper towels.
Preheat the oven to 350 degrees F
Remove turkey from brine and place into a roasting pan. Pat dry turkey. Combine mayonnaise, olive oil, garlic powder, onion powder, paprika, Italian seasoning, salt and black pepper. Rub this mixture all over the turkey breast and under the skin. Place in the oven and roast for about 1 1/2 hours or until the turkey reaches 165 degrees F on an instant-read thermometer. Make sure to let the turkey rest before slicing.
Slice the turkey and assemble the sandwiches by topping 1 piece of bread with the Cilantro Mayonnaise Sauce, turkey, bacon, another piece of bread, Cilantro Mayonnaise Sauce, turkey, tomato, lettuce, avocado, and a final piece of bread spread with the Cilantro Mayonnaise Sauce. Repeat with remaining bread and ingredients.
Cilantro Mayonnaise Sauce:
Combine all the ingredients and mix well.
In a large saucepan filled with ice, pour brine and mix, allowing ice cubes to melt. Brine should be cool to the touch.