Preheat your oven to 425 degrees.

Warm up your meatballs and sauce. Although you'll be baking these sandwiches, it's better if your ingredients are already warm. If I'm using my own meatballs and making my own sauce, I just let it all simmer together in the slow cooker for a few hours. If I'm using store bought ingredients, I combine it all into a pot on the stove and let it heat up for a few minutes.

Butter the insides of your bun. Sprinkle with garlic powder, if desired.

Place on a cookie sheet with the buns open. Bake for about 5 minutes just to brown the buns.

Place meatballs on the buns. If using really big meatballs, you can slice them in half. That makes it easier to bite into - especially for kids.

Make sure the meatballs have some sauce - not too much, but you don't want the sandwiches dry either.

Sprinkle sandwiches with cheese.

Press sandwiches together and bake for another 5 minutes to melt cheese. You can bake on the cookie sheet or press the sandwiches side-to-side in a 9x13 baking pan.

Serve!