1-Gather all ingredients, measure the pasta, cheese, milk, and seasonings to ensure smooth preparation.

2-Lightly grease the crockpot to prevent sticking.

3-Add uncooked elbow macaroni and pour in milk and cream evenly.

4-Stir in mustard powder, salt, and half of the shredded cheese into the mixture.

5-Cover the crockpot and cook on low for 2.5 to 3 hours, stirring halfway to avoid clumping and sticking.

6-About 30 minutes before serving, add the remaining cheese and butter to melt, stirring well for a creamy consistency.

7-Taste and adjust seasoning, optionally adding pepper or extra spices based on preference.

8-Serve hot directly from the crockpot with garnishes such as chopped herbs or breadcrumbs. Adapt vegan, gluten-free, or low-calorie versions by adjusting ingredients accordingly at each step.

9-Spray a 6-quart slow cooker with non-stick spray. Rinse uncooked pasta in cold water and drain. Combine the pasta, whole milk, evaporated milk, shredded cheeses, salt, pepper, mustard, garlic powder, and cayenne pepper in the slow cooker. Stir to mix, ensuring the pasta is mostly submerged. Dot the top with cubed butter. Cover and cook on low for 1 hour, then remove the lid and stir quickly. Replace the lid and continue cooking, checking every 30 minutes, for up to 3 hours total depending on the slow cooker. The pasta is done when it is tender and the sauce is thick and creamy; the sauce will thicken further as it rests with the lid off. The preparation time is about 2 hours cook time, with a total of around 2 hours and 20 minutes.