Heat the oven to 400°F. Lightly grease 8 cups of a standard muffin tin.
In a large bowl, combine the ground beef, breadcrumbs, egg, pesto, Parmesan, salt, and black pepper. Mix gently until just combined, taking care not to pack the mixture too firmly.
Divide the mixture among the 8 greased muffin cups. Press it in lightly and shape the tops evenly.
Bake for 18 to 22 minutes, until the mini meatloaves are cooked through. Let them rest in the tin for 5 minutes before removing.
While the meatloaves bake, combine the halved cherry tomatoes, olive oil, red wine vinegar, and chopped basil in a bowl. Toss gently and let the salad sit until serving.
Serve the pesto Parmesan meatloaf muffins warm with the cherry tomato salad alongside.