Preheat oven to 350 degrees F. Bring a large pot of lightly salted water to a boil. Spray a muffin tin liberally with cooking spray.
Cook pasta according to package directions, drain, and set aside.
While pasta cooks, heat a skillet over medium-high heat. Add diced bacon, and cook, stirring occasionally, until brown and most of the fat has rendered. Scoop out the cooked bacon with a slotted spoon, and place on a plate lined with paper towels to drain.
In a large mixing bowl, lightly beat the egg. Add two cups of shredded cheese, ricotta, yogurt, ranch seasoning, and milk. Whisk until smooth. Stir in cooked pasta and most of the cooked bacon, saving about 1/4 cup for the topping.
Scoop the macaroni mixture into the prepared muffin tin. It’s OK for pasta to be mounded up above the edge of the pan.
In a small bowl, stir together remaining 1/2 c. shredded cheese, 1/4 c. cooked bacon, and dill. Sprinkle about a tablespoon of this mixture on top of each mac and cheese cup. Bake in preheated oven for 20-25 minutes, until edges are brown and topping is melted and bubbly.
Allow to cool in pan for at least 10 minutes. Carefully run a butter knife around the edge of each mac and cheese cup to loosen it from the pan, and serve immediately or place on a wire rack to cool before storing.