In a large pot of salted boiling water, cook macaroni pasta according to package instructions and drain.
In medium pot, whisk together butter and flour. Slowly whisk in milk and cook on medium-low heat until mixture thickens enough to coat the back of a spoon.
Reduce heat to low. Add shredded Imported Cheddar and Imported Neufchatel cheese, continue to whisk until incorporated and smooth. Mix in egg yolk. Remove from heat.
Stir cooked pasta into mixture.
Butter bottom and sides of muffin tins and sprinkle half of the Imported Parmiggiano Reggiano around the edges to coat completely. Divide mac and cheese into each cup and top with the remaining Imported Parmigiano Reggiano.
Bake approximately 15 minutes and allow to cool 5 minutes before removing from the tins and serving.
Keyword imported extra sharp cheddar, imported parmigiano reggiano, mac and cheese cups