Prepare a small rimmed baking sheet with tin foil and an even layer of nonstick spray and prepare a 9-inch loaf pan with a light coating of nonstick spray.

Preheat the oven to 325 °F with a convection fan (or 350 °F without a fan).

Combine the buttermilk, bread crumbs, and garlic powder in a medium bowl. Reserve until ready to use.

In a large bowl, combine the vegetables with the meatloaf mix, buttermilk mixture, tomato paste, parsley, basil, eggs, Worcestershire sauce, salt, and 1 teaspoon of pepper. 

Gently fold the ingredients together with your hands. Try to avoid squeezing the meat as much as possible while still achieving a homogenous mixture.

Press the meatloaf mixture into the prepared loaf pan. Flip the meatloaf out onto the foil-lined baking sheet. 

Meanwhile, prepare the glaze by combining the ketchup, tomato paste, brown sugar, honey, vinegar, Worcestershire sauce, and remaining pepper in a small bowl. Whisk to combine. 

Bake the meatloaf for 15 minutes, then brush it with about half of the glaze.

Bake for an additional 15 minutes, and then brush the remaining glaze over the meatloaf and place it back in the oven. Continue cooking until the internal temperature reaches 155 °F, about 20-25 minutes.

Remove the meatloaf from the oven and allow it to cool on a rack for 10 minutes before slicing and serving.