Place the cauliflower and carrots onto a large baking sheet. Drizzle with olive oil and season with garlic powder, salt, and cumin. Toss to coat.
Meanwhile, cook pasta according to package directions. Reserve ½ cup pasta water, drain, return into the pot, and set aside.
Once the veggies are cooked, remove from oven and transfer them inside a food processor or blender and add the nutritional yeast and Quaker Original Unsweetened Oat Beverage. Blend until smooth.
Pour the creamy purée on the pasta and warm, over medium-low heat, while stirring to combine. Add a small amount of pasta water at a time until you have the consistency of the sauce you like. Serve warm.