Preheat oven to 400 degrees. Line a cookie sheet with foil and spray with cooking spray or coat in olive oil.

Chop the first hamburger bun or slices of bread up into 1/2 inch by 1/2 inch squares (roughly). Combine them in a bowl with buttermilk. Let sit for about 5 minutes, or until bread is soaked.

Add the yolk, red pepper flakes, Italian seasoning, kosher salt, pepper, minced garlic, parmesan, and onion powder to the bread and smash and combine with a rubber spatula or fork until paste-like in consistency. Add the ground beef and combine using your hands until well-incorporated.

Separate the ground beef into ten same-sized balls. Roll each into a round ball squish down slightly, and pull two ends together to create the football shape. Line them up on the foil-lined cookie sheet.

Bake the meatballs in the oven for 12-15 minutes, until cooked through.

While they’re cooking, combine the tomato sauce, stewed tomatoes, Italian seasoning, salt, garlic powder, and onion powder in a medium sized sauce pan on medium-low heat. Cook for a few minutes to heat. If you like a chunky sauce, leave as is. If you like a smoother sauce, use an immersion blender to break up the tomatoes. It’ll be a thick sauce.

Cut one of the slices of mozzarella into thin strips. Immediately after removing the meatballs from the oven, arrange the strips as laces on the meatballs.

Toast the remaining hamburger buns. Top the buns with a meatball, 1-2 slices of mozzarella, and sauce. Cheese will melt slightly from the heat of the sauce and meatballs, but if you want it to be really melty, put sandwiches under the broiler for a minute or so.