Pre-heat the oven to 350 degrees. Lightly mist a 2 quart casserole dish (mine is a 7x11 Pyrex) with cooking spray and set aside.
Crack the eggs into a large mixing bowl and lightly beat with a fork. Add the ground turkey and ground beef and mush them together to combine.
In a small bowl, mix together the dried minced onion, celery salt, garlic powder, thyme, paprika, and black pepper. Pour the spice mixture over the meat in the large mixing bowl. Add the breadcrumbs, milk, and ketchup to the bowl and use clean hands or a fork to mix the ingredients together until well combined. Transfer the meat mixture to the prepared casserole dish and spread evenly throughout the dish.
Transfer the casserole dish to the heated oven and cook for 45-50 minutes until cooked through (should have an internal temperature of 160 degrees).
When there is about 10 minutes left on the meatloaf, stir the flour and Cajun seasoning together in a small dish. Melt the butter in a medium saucepan over medium heat. When the butter is melted, whisk in the Cajun flour a little at a time. Cook for 1-2 minutes, stirring occasionally. Add the broth a little bit at a time, whisking it into the flour mixture until smooth and well combined. Add the bouillon and Gravy Master. Whisk regularly until the gravy comes to aboil and thickens. Remove from heat and allow to sit for at least 5 minutes to thicken.
When the meatloaf is ready, slice it into 12 equal slices. Each serving is 2 slices of meatloaf and 1/3 cup of gravy.