Brown ground beef and diced onion in a pan, then add to your crockpot.
Pour can of spaghetti sauce and can of diced tomatoes on top of meat.
Sprinkle taco seasoning on top, stir well.
Set crockpot to high and cook for 3 hours, or low and cook for 5-6 hours.
Lift lid when done cooking and add your uncooked noodles and 1 cup of cheese, (and ricotta if you choose to add it) stir well.
Sprinkle other 1/2 c. of cheese on top and put lid back on.
Set to high for 30 minutes.