Ingredients :

• Frozen cheese ravioli — Choose the ricotta-spinach filled ones if you can find them: the spinach disappears into the sauce but adds an earthy undertone that balances the acidity of the tomato. Avoid fresh ravioli from the refrigerated section—they fall apart too quickly in the slow cooker.
• Ground beef — Get beef with at least 15% fat. Lean beef results in a dry sauce and grainy bits. If you want to lighten it up, half beef and half ground turkey works great—the sauce stays flavorful.
• Jarred marinara sauce — Don’t skimp here. The marinara accounts for 60% of the final taste. A good sauce—Mutti, Rao’s, or any serious brand in your aisle—really changes the result compared to the cheapest option.
• Ricotta — It gets mixed with the meat before assembly. As it melts gently, it creates little creamy pockets between the ravioli layers. If you don’t have any, basic cream cheese works fine without much difference.