Add the ground beef, onion, and garlic. Cook, stirring often to break up the meat, until it’s browned, about 5 to 10 minutes.
Pour in the crushed tomatoes and tomato sauce.
Season with salt, oregano, basil, and red pepper flakes.
Stir well and let the sauce simmer for about 5 minutes.
In a small bowl, mix together the ricotta and 1 cup of mozzarella.
Spoon one-third of the meat sauce into the bottom of the crock pot.
Break three lasagna noodles in half and place them on top of the sauce.
Spread half of the ricotta mixture evenly over the noodles.
Add another one-third of the meat sauce on top.
Layer the remaining noodles over the sauce.
Spread the rest of the ricotta mixture on top.
Finish with the last third of the meat sauce.
Cover the crock pot and cook on Low for 4 to 6 hours.
In a separate small bowl, combine the remaining ½ cup of mozzarella with the Parmesan cheese. Sprinkle the cheese mixture over the cooked lasagna.
Cover again and let it sit for about 10 minutes, until the cheese melts and the lasagna sets.
Notes
How to Store and Reheat
Store: Cool completely. Cover and refrigerate up to 4 days.
Freeze: Wrap individual squares tightly and freeze up to 2 months.
Reheat (Microwave): Cover a slice and heat on medium power in 45- to 60-second bursts until hot.
Reheat (Oven): Place in a small baking dish, cover with foil, and warm at 325°F until heated through, about 15 to 20 minutes. Add a spoon of sauce or a splash of water to keep it moist.