1. Preheat oven to 350F. 

2. Boil pasta in salted water, until al dente. Cool down pasta immediately by running cold water over it.

3. In a medium saucepan, put the milk, thyme sprigs, bay leaf and onion with cloves. Bring up to a simmer and turn off heat.

4. In another large pan, melt the butter over medium heat. 

5. Add the flour and stir constantly until the roux turns just barely nut brown.

6. Add half of the milk, through a strainer, whisking constantly to avoid lumps. 

7. Add the rest of the milk and cook the béchamel until thickened, stirring frequently. When the béchamel coats the back of a spoon, remove from the heat and add nutmeg, paprika and salt.

8. Add the cheeses to the béchamel and stir well to melt the cheeses. Stir until the béchamel is thick and uniform.

9. In a large bowl, mix the pasta with the béchamel, and then gently fold in the squash.

10. Butter a 9’ x 13’ baking dish. 

11. Spoon or pour the mixture into the dish. 

12. Melt the 2 tablespoons of butter. Toss the breadcrumbs in the butter to coat. 

13. Add the chopped thyme and Parmesan.

14. Evenly sprinkle the breadcrumbs over the pasta mixture. 

15. Bake in a 350° F oven until the topping is golden brown and the cheese on the edges has bubbled a bit. 

Let cool for about 5 minutes before eating.