Step 1

Preheat oven to 350 F.

Step 2

Cook pasta for 1 minute less than package directions for al dente pasta.

Step 3

Meanwhile, heat a large oven-proof skillet over medium heat, and add in olive oil.

Step 4

Stir in onion and garlic. Cook for about 4-5 minutes, stirring regularly.

Step 5

Add in marinara sauce, cooked meatballs, and cooked pasta. Stir to combine.

Step 6

Top with slices of mozzarella.

Step 7

Bake for about 10 minutes, or until cheese has melted and pasta is hot and bubbly.