First, lightly grease your slow cooker insert with butter or cooking spray – this will prevent that dreaded crusty ring around the edges that’s such a pain to clean later.

Add cubed butter, cream cheese, and Velveeta. Break up the cream cheese into smaller chunks if you can – it’ll melt more evenly this way. Scatter your freshly grated cheddar over top (pre-shredded cheese won’t melt as smoothly, so grating your own makes a big difference).

Sprinkle in the salt, pepper, garlic powder, and paprika. Give everything another gentle stir to combine.

Cover and cook on LOW for 2½ to 3 hours. The key is to stir every 30 minutes or so. You’ll notice the mixture getting progressively thicker and creamier each time you stir. The pasta is done when it’s tender but still has a slight bite – you don’t want it mushy!

When the pasta is cooked through, give it one final stir. The sauce might look a bit thin at first, but let it sit for about 5-10 minutes with the lid off – it’ll thicken up beautifully as it cools slightly. If it gets too thick, just stir in a splash of warm milk until you reach your desired consistency.

Your mac and cheese is ready when you can pull a spoon through it and it leaves a trail that slowly fills back in, kind of like hot lava. The surface should look glossy and smooth, not grainy or separated.