Fire up the pellet grill and set it to 225 degrees Fahrenheit. Allow it to preheat fully with the lid closed for at least 15 minutes. Load your hopper with hickory or cherry wood pellets - hickory delivers that classic bold BBQ smoke while cherry gives a slightly sweeter profile and helps the bark develop a gorgeous deep red color. You want the grill stabilized at temp before the meatloaf goes on.

While the grill comes up to temp, make your panade by combining the plain breadcrumbs and whole milk in a small bowl. Stir them together and let the mixture sit for 5 minutes until the breadcrumbs fully absorb the milk. This step is non-negotiable - it is the secret weapon that keeps your smoked meatloaf from drying out over the long cook.

In a large mixing bowl, combine the ground beef, ground pork, soaked breadcrumb panade, lightly beaten eggs, grated onion, minced garlic, Worcestershire sauce, yellow mustard, smoked paprika, garlic powder, onion powder, kosher salt, black pepper, and cayenne if using. Mix everything together with your hands until just combined. Do not overwork the meat - overmixing develops too much protein structure and results in a dense, tough loaf. Mix until you no longer see streaks of individual ingredients, then stop.

Turn the meat mixture out onto a clean work surface or a large sheet of parchment paper. Shape it into a free-form loaf approximately 9-inch long, 5-inch wide, and 3-inch tall. A free-form loaf rather than a loaf pan is essential for smoked meatloaf because it allows smoke to hit all four sides and the top, maximizing bark development and smoke penetration. Place the shaped loaf on a wire cooling rack set over a rimmed baking sheet or aluminum drip pan.

Make the BBQ glaze by whisking together your favorite BBQ sauce, brown sugar, and apple cider vinegar in a small bowl until the sugar dissolves. Set aside half of this glaze for serving - you never want to cross-contaminate a sauce that touches raw meat with your finishing sauce.

Place the wire rack with the meatloaf directly onto the pellet grill grates. Close the lid and let it smoke undisturbed at 225 degrees Fahrenheit for 2.5 to 3 hours. Resist the urge to open the lid repeatedly - every time you peek, you lose heat and smoke. At the 2-hour mark you should start seeing a deep bark forming on the outside and the first signs of a smoke ring developing just beneath the surface. The internal temp at this point should be somewhere around 130 to 140 degrees Fahrenheit.

Once the internal temp hits 140 degrees Fahrenheit, crank the pellet grill up to 325 degrees Fahrenheit. Apply the first generous coat of your BBQ glaze all over the top and sides of the meatloaf using a silicone basting brush. Close the lid and let it cook for another 15 minutes.

After 15 minutes, apply a second coat of the BBQ glaze. The sugar in the glaze is starting to caramelize now and you will see it develop a sticky, lacquered finish. Close the lid and continue cooking for another 10 to 15 minutes, checking the internal temp with your instant read thermometer inserted into the thickest center part of the loaf. You are looking for a final internal temp of 160 degrees Fahrenheit to ensure the meatloaf is fully cooked through and safe to eat.

Once the internal temp reads 160 degrees Fahrenheit, remove the meatloaf from the pellet grill and let it rest on the wire rack for a full 10 to 15 minutes before slicing. Resting the meat is critical - it allows the juices that have been driven toward the center during cooking to redistribute evenly throughout the loaf. Cut into it too soon and all those juices run out onto the cutting board. After the rest, slice it into thick 1-inch slices and serve with the reserved BBQ glaze on the side.