Preheat the oven to 350F.
In a food processor, add the mushrooms and pulse until roughly chopped—you don’t want the mushrooms to be totally ground, but keep them small enough that they’ll seamlessly blend with the ground turkey.
To a large skillet over medium-heat, add the olive oil. Add the mushrooms and diced onions and sauté until soft, about 5-7 minutes. Add the garlic and cook until aromatic, about 2 minutes.
Meanwhile, wipe out the food processor with a clean, wet paper towel. Add the crackers and pulse until finely ground, like a flour.
In a large glass bowl, combine the ground crackers with the ground turkey, egg and ketchup. Season with salt and pepper. Add the cooked mushrooms and onions and allow mixture to cool enough to touch (about 5-10 minutes). Once cooled, use your hands to mix the meatloaf together, being careful not to overmix (you want the ingredients just combined).
To a baking sheet, add the meatloaf mixture. You can make one large meatloaf, or split the mixture in half to make two smaller loaves. Bake for 45 minutes. Using a pastry brush, paint the BBQ sauce over the meatloaf. Bake for another 15 minutes, or until an internal meat thermometer reads 165F. Serve and enjoy!