Cooling/Resting Time: 0 minutes
Preheat oven to 375F.
Toss butternut squash with olive oil, thyme, sage, and salt, then roast on parchment-lined baking sheet for 20-25 minutes until fork tender.
Blend roasted squash in food processor until smooth, then slowly add heavy cream while processing until thick soup consistency.
Cook pasta shells until al dente according to package directions, drain, cover, and set aside.
In same pot, melt 1/4 cup butter over medium heat, whisk in flour, and cook for 1 minute.
Slowly whisk in milk to prevent lumps.
Whisk in butternut squash mixture, nutmeg, garlic powder, onion powder, and mustard powder.
Simmer until slightly thickened, 3-4 minutes.
Whisk in cream cheese until smooth, then remove from heat.
Gradually whisk in cheddar and gouda until melted and smooth.
Fold cooked pasta into cheese sauce until well coated.
Season with salt to taste.
Grate parmesan over mac and cheese.
Melt 3 Tbsp butter in small skillet over medium heat, add garlic, sage, and thyme, and cook until fragrant, 1 minute.
Stir in crushed crackers and cook for 3 minutes until lightly golden.
Sprinkle cracker topping over mac and cheese and serve immediately.