This turned out amazing. I cobbled it together from a few different recipes and incorporated the rosemary on my own, so I’m posting the recipe here as much for memorializing it myself as anything. Obviously you can use whatever cheese you like but I wanted a strong cheddar combined with a mild and creamy cheese for texture.
1 (16-oz) box small shells
½ cup butter
½ cup all-purpose flour
4 cups milk
1 lb butterkase cheese, grated (Muenster, Gouda, havarti, similar cheese is fine)
1 lb sharp white cheddar cheese, grated
Salt, pepper, garlic powder to taste
Dash cayenne pepper
2 cups fresh bread crumbs (french bread or brioche buns in a food processor works well)
3 Tbsp butter, melted
Fresh rosemary, finely chopped
Preheat oven to 350ºF. Grease a 9x13x2-inch baking dish.
Cook pasta 2 minutes shy of al dente directions. Drain.
In a large saucepan, melt ½ cup butter. Slowly whisk in the flour and cook for 1 to 2 minutes.
Slowly whisk in milk until well blended. Reduce heat to medium and cook 5 minutes, until thickened.
Stir in butterkase and cheddar cheeses. Remove from heat.
Stir in salt, pepper, cayenne pepper and garlic powder.
Combine cheese sauce and pasta, stir to coat. Spoon pasta into prepared pan.
Combine fresh bread crumbs, melted butter, and rosemary. Sprinkle on top of pasta.
Bake uncovered for 15 to 20 minutes, until topping is golden brown.