Use an aluminum cake pan that’s 8.5 inches in diameter. This fits perfectly into my air fryer and holds the liquid ingredients as needed.
Add a layer of frozen meatballs to the cake pan.
Pour a jar of marinara sauce (we use Muir Glen or Rao’s low carb versions) over the meatballs.
Top the meatballs with mozzarella cheese.
Cover the top with a sheet of aluminum foil to prevent the cheese from burning.
Bake at 350 degrees for about 15 minutes. Remove the foil about 5 minutes before it’s done so the cheese can melt on top.
Optional: Add a layer of keto bread at the bottom of the tray before adding the meatballs if you choose to consume keto bread with this casserole recipe.