Step 1: Prepare the Sweet Potato Gnocchi Dough

1. Preheat the oven to 400°F (200°C), and bake the sweet potatoes until soft and tender (about 45 minutes). Alternatively, microwave them for 8-10 minutes until cooked through. Allow the sweet potatoes to cool slightly before peeling.
2. In a large mixing bowl, mash the sweet potatoes until smooth. If you’re using ricotta cheese, stir it in at this stage.
3. Add the beaten egg, salt, pepper, and nutmeg (if using), and mix until well combined.
4. Gradually add the flour, 1/2 cup at a time, mixing after each addition. The dough should be soft but not sticky. Depending on the moisture in the sweet potatoes, you may need between 1 ½ to 2 cups of flour. Be careful not to overwork the dough, as it should remain light and tender.

Step 2: Shape the Gnocchi

1. Lightly flour a clean surface and divide the dough into four equal portions.
2. Roll each portion into a long rope about 1/2 inch in diameter.
3. Cut the ropes into 1-inch pieces using a sharp knife or dough cutter.
4. Optional: For traditional gnocchi ridges, gently roll each piece over the back of a fork or a gnocchi board to create indentations. This helps the gnocchi hold the sauce better.
5. Place the shaped gnocchi on a floured tray while you continue with the rest of the dough.

Step 3: Cook the Gnocchi

1. Bring a large pot of salted water to a boil.
2. Gently drop the gnocchi into the boiling water, working in batches if necessary. They will sink to the bottom initially.
3. Cook until the gnocchi float to the top, about 2-3 minutes. Once they float, let them cook for another 30 seconds before removing with a slotted spoon.
4. Transfer the cooked gnocchi to a paper towel-lined plate to drain any excess moisture.

Step 4: Brown the Butter and Fry the Sage

1. In a large skillet, melt the butter over medium heat. Continue to cook, swirling the pan occasionally, until the butter turns golden brown and begins to develop a nutty aroma. This should take about 4-5 minutes.
2. Add the fresh sage leaves to the hot butter and cook for about 1 minute, until they become crispy. Be careful not to burn them.
3. Remove the crispy sage leaves from the pan and set them aside on a paper towel to drain.

Step 5: Pan-Fry the Gnocchi

1. Add the cooked gnocchi directly into the brown butter in the skillet.
2. Toss the gnocchi gently in the butter to coat evenly, and pan-fry for 2-3 minutes, until the gnocchi develop a slight golden crust.
3. Season with salt and pepper to taste, and remove from heat.

Step 6: Assemble the Dish

1. Transfer the gnocchi to a serving dish or individual plates.
2. Sprinkle generously with freshly grated Parmesan cheese.
3. Crumble the crispy sage leaves over the top.
4. Optional: Garnish with additional Parmesan and a light drizzle of extra brown butter for extra richness.