Brown Butter Sweet Potato Alfredo

2 Tbsp unsalted butter, browned - 1 medium sweet potato (cubed into 2-inch cubes) - 2 Tbsp all-purpose flour - 1 cup whole milk - 1 & 3/4 cup water (divided) - 1 cup freshly grated Parmesan cheese - 1 pound cooked spaghetti - 1/4 Tsp cayenne pepper (more or less depending on heat preference) - Salt and pepper, to taste - Green onion for garnish (sliced on a bias)

Bring a pot of water to a boil and add the cubed sweet potatoes and cook until fork tender. Carefully place sweet potatoes into a blender and Purée until smooth. In a large pot over medium heat, add the brown butter and whisk together with flour for 30 seconds. Turn the heat up to medium-high and carefully add the milk and continue whisking until mixture thickens, about 3-4 minutes. At this time, add the Puréed sweet potatoes and 1 & 1/2 cup of water. Let the mixture simmer for 5-7 minutes until thickened then add the Parmesan cheese, cayenne, salt, pepper, and turn off the heat. If the mixture seems too thick, you can add the remaining 1/4 cup of water to thin it out. Add the cooked pasta to the pot and toss until well-coated. Garnish with green onion.