First things first, let's get that meat cooking! Brown your ground beef (or sausage) in a large skillet over medium-high heat. Break it up with a spoon as it cooks – we're looking for nice, small pieces here. Once it's browned, drain off the excess fat, then add your diced onion to the same pan. Let it cook until it becomes soft and translucent, about 5 minutes. Add the garlic and cook for just another minute until it becomes fragrant. Your kitchen should be smelling amazing right about now!

Time to build your sauce! In your slow cooker, combine the crushed tomatoes, tomato sauce, oregano, basil, salt, and pepper. Add your meat mixture and give everything a good stir.

Here's where the magic happens – add your uncooked pasta right to the slow cooker. I know it seems strange if you've never done it before, but trust me on this one! Make sure all the pasta is well-coated with sauce. Add 1 cup of water or chicken broth – this extra liquid is crucial for cooking the pasta properly. Pro tip: The liquid might seem like a lot at first, but the pasta will absorb it as it cooks, creating the perfect texture.

Now for the cheese! Drop spoonfuls of ricotta throughout the mixture. Don't worry about mixing it in completely – those pockets of creamy ricotta will be delicious surprises later.

Cover and cook on low for 4-6 hours or on high for 2-3 hours. The pasta should be tender but not mushy. About 30 minutes before serving, sprinkle the mozzarella cheese over the top and let it melt into gooey perfection.

Before serving, give everything a gentle stir and garnish with fresh parsley.