Preheat the oven to 400°F (200°C). Place the pierced sweet potatoes on a baking sheet and roast for about 1 hour, or until very tender. Let them cool slightly, then scoop out the flesh and mash until smooth. Measure 3 cups and transfer to a large mixing bowl.
3 medium sweet potatoes
Add ricotta, Parmesan, egg, and salt to the mashed sweet potatoes. Stir until combined.
2 cups ricotta cheese, ⅔ cup grated Parmesan cheese, 1 large egg, 2 teaspoons salt
Gradually mix in the flour, ½ cup at a time, kneading gently after each addition. Use just enough flour to form a smooth, soft dough that’s not sticky. Do not overwork the dough.
3 ½ to 4 ½ cups all-purpose flour
Lightly flour your work surface. Divide the dough into 8 portions. Roll each portion into a long rope about ½ inch thick. Cut into ½-inch pieces. Optional: Roll each piece over the back of a fork or gnocchi board to make ridges. Transfer to a parchment-lined baking sheet dusted with flour.
Bring a large pot of salted water to a boil. Work in batches to avoid overcrowding.
Drop the gnocchi into the boiling water. Once they float to the surface (about 2–3 minutes), remove them with a slotted spoon and place them on a lightly greased baking sheet.
In a large skillet, melt the butter over medium heat. Let it cook for 4–5 minutes, swirling occasionally, until it turns golden brown and smells nutty. Remove from heat and stir in the chopped thyme. Season with salt and pepper.
1 cup unsalted butter, 5 tablespoons fresh thyme, Salt and pepper
Heat a clean skillet over medium-high heat. Add a portion of the brown butter and half of the gnocchi. Sauté for 5–6 minutes, or until golden and lightly crispy. Transfer to a warm oven 300°F (150C) while you sauté the remaining gnocchi.
Plate the gnocchi and drizzle with the remaining brown butter thyme sauce. Top with freshly grated Parmesan and enjoy warm.
Freshly grated Parmesan