In a blender, add soaked (and drained) cashews + pumpkin puree + garlic + salt + pepper + paprika + maple syrup + nutritional yeast + soy milk. Blend well until the mixture is smooth. Set aside.
Set a large pan over medium heat. Add vegan butter. Once it's hot, add dried rosemary and saute for 10 seconds. Then add all-purpose flour and mix-cook for 2 minutes, or until the lumps are gone.
Stirring continuously, add the blended cashew-pumpkin mixture (in small portions). Mix well.
Continue stirring and bring the mixture to a gentle simmer. Turn down the heat to low-medium and keep simmering for 2 minutes. Once it's thickened, add the cooked pasta and coat well.
Creamy pumpkin pasta is ready. Garnish with chili flakes and serve hot.