METHOD

1. In a large pot over high heat, boil enough salted water to cook the pasta. Add elbow macaroni and cook until just barely al dente, about 6 minutes (or 3 minutes less than whatever the box recommends). Drain and set aside.
    
2. In a large saucepan over medium heat, melt the butter. Sprinkle in the flour, then stir to combine with the melted butter. Allow to cook for 1 minute, then add the milk. Cook, whisking occasionally, until the sauce thickens.
    
3. Add in the Bel Paese, Mozzarella, and grated Parmesan cheeses, constantly stirring until fully incorporated.
    
4. Turn off heat. Add in pumpkin puree, pumpkin pie spice, and sage, and stir to blend fully with wooden spoon. (For added sweetness, add the optional agave to the sauce.)
    
5. Whip the Mascarpone cheese and heavy cream on high speed until it becomes light, smooth, and airy.
    
6. When the cheese mixture is cooled to room temperature, gently fold in the whipped Mascarpone. (This should make the mixture lighter.)
    
7. Slowly add the cooked elbow macaroni to the mixture, using a large spatula to fully incorporate pasta. Handle gently.
    
8. Transfer the pasta mixture to an ovenproof serving bowl and top with garlic breadcrumbs. Season with black pepper.
    
9. Bake at 350 degrees for 8 minutes, then finish with broil for 3–4 minutes until breadcrumbs are golden brown and crunchy.
    
10. Remove from oven and garnish with fried sage and shaved Parmesan.