Fill a pot with 2-inches of canola oil and heat it to 375 degrees F. Preheat the oven to 400 degrees F.
Arrange the bacon on a sheet tray with a rack. Brush the bacon with even amounts of maple syrup. Bake until crisp, about 18 to 22 minutes. Remove the bacon from the oven to a paper towel lined platter. Set aside.
Combine the flour, cayenne, and salt and pepper, to taste, in a medium-sized bowl. Add the sliced shallots and toss the shallots in the flour to coat evenly. Shake off excess flour. Working in 2 batches, fry the shallots until crisp, about 2 to 3 minutes. Remove them to a paper towel lined platter and sprinkle with salt. Set aside.
In a small bowl, mix together the mayonnaise, chipotles, adobo sauce, cilantro, lemon and garlic until well combined. Season with salt and pepper, to taste. Set aside.
Slice the turkey breast into 1/4-inch slices. Lay the bread out on a large cutting board. Spread chipotle mayonnaise on each slice of bread. Top each slice of bread with a slice of smoked Cheddar and a couple slices of bacon. Sprinkle some crispy shallots on 3 slices of bread. Put a few slices of turkey on top of the onions. Sprinkle some additional shallots on the turkey. Form 3 sandwiches and spread each sandwich with a little melted butter. Put the sandwiches in a large skillet over medium heat. Cook, pressing down the sandwich with a spatula, for 3 to 4 minutes on each side. Remove the sandwiches from the pan and serve.