Preheat the oven to 375°F (190°C) and spread the diced butternut squash on a parchment-lined baking sheet. Roast 25–30 minutes until fork-tender and lightly caramelized at the edges—this builds sweetness and keeps the sauce from tasting raw.

Cook the shells in well-salted boiling water according to package timing, then drain. Pull it when it’s al dente (still has a little bite) so it doesn’t turn soft after you coat it in hot sauce.

In a blender, combine the roasted squash, soaked cashews, nutritional yeast, garlic powder, onion powder, Dijon, paprika, turmeric, vegetable broth, olive oil, salt, and black pepper. Blend until completely smooth and creamy—if it looks grainy, keep blending and don’t add extra liquid too fast.

Pour the sauce over the warm pasta and stir until every shell is coated and glossy, adding a small splash of broth only if it feels too thick. Taste and adjust with a pinch more salt and pepper until it pops, then serve immediately while it’s hot and velvety.