Gnocchi Ubi Jalar dengan Saus Krim Rosemary Parmesan

Bahan-bahan (6 porsi)

• 2 medium sweet potatoes (about 2 cups once mashed)
• 1/2 cup whole milk ricotta
• 1 large egg
• 2 -3 cups all-purpose flour
• 1 teaspoon kosher salt
• 4 tablespoons (1/4 cup) butter
• 1 tablespoon chopped fresh rosemary
• 1 cup heavy cream
• 1/3 cup fresh grated parmesan, plus more for serving
• pinch fresh grated nutmeg
• pinch cayenne pepper
• kosher salt and pepper