In a bowl, mix ricotta cheese, eggs, and fresh basil.

In another bowl, combine the two jars of pasta sauce with the tomato sauce.

Spray a 6‑quart (or larger) slow cooker lightly with cooking spray for easy cleanup.

Pour about 2 ⅓ cups of the sauce mixture into the bottom of the slow cooker.

Add one-third of the uncooked penne pasta evenly over the sauce.

Dollop or layer half of the ricotta mixture over the pasta.

Sprinkle with half of the Parmesan cheese.

Repeat: another 2 ⅓ cups of sauce, one-third of the pasta, the remaining ricotta mixture, and the remaining Parmesan cheese.

Top with the final third of the pasta and cover with the remaining sauce to ensure everything cooks evenly.

Cover and cook on high for approximately 2 hours and 15 minutes, watching closely toward the end to avoid overly soft noodles.

Sprinkle shredded mozzarella over the top and cook an additional 15 minutes, until melted and bubbly.