Preheat the oven to 350°F.
Generously coat a standard 12-cup muffin tin with cooking spray.
Bring a large pot of lightly salted water to a boil.
Add the macaroni or rotini and cook according to the package directions.
Drain the pasta thoroughly and set it aside.
While the pasta cooks, place the diced bacon in a skillet over medium-high heat.
Cook the bacon, stirring occasionally, until browned and most of the fat has rendered.
Using a slotted spoon, transfer the cooked bacon to a paper towel-lined plate to drain.
In a large mixing bowl, lightly beat the egg.
Add 2 cups of the shredded sharp cheddar cheese, ricotta cheese, plain yogurt or sour cream, ranch dressing mix, and milk.
Whisk until the mixture is smooth and evenly combined.
Add the cooked pasta to the cheese mixture.
Stir until the pasta is fully coated.
Add most of the cooked bacon, reserving approximately 1/4 cup for the topping.
Stir gently until the bacon is evenly distributed throughout the pasta mixture.
Divide the macaroni mixture evenly among the prepared muffin cups.
The pasta may be slightly mounded above the edge of each muffin cup.
In a small bowl, combine the remaining 1/2 cup shredded cheddar cheese, the reserved 1/4 cup cooked bacon, and the minced dill.
Sprinkle approximately 1 tbsp of the cheese, bacon, and dill topping over each mac and cheese cup.
Bake for 20 to 25 minutes, or until the edges are browned and the topping is melted and bubbly.
Remove the muffin tin from the oven.
Allow the mac and cheese cups to cool in the pan for at least 10 minutes.
Carefully run a butter knife around the edge of each cup to loosen it from the pan.
Remove the cups gently and serve warm, or transfer them to a wire rack to cool before storing.