Preheat the oven to 400 degrees. Line a baking sheet with parchment paper.
Pierce the sweet potatoes with a fork or knife and place onto the prepared baking sheet. Bake for about 1 hour or until tender. Let cool completely.
Once completely cooled, cut in half. Scoop the sweet potato into a bowl and mash. Transfer 1 ½ cups of sweet potato to a medium bowl and mix in ricotta, parmesan, egg, garlic, salt, and pepper. Slowly add in the flour, ½ cup at a time until a dough forms. Be careful not to over-knead the dough.
Lightly flour a work surface. Transfer the dough from the bowl to the floured work surface. Divide the dough into 6 even pieces. Roll each piece into a long rope, about 1 inch in diameter. Using a sharp knife, cut into bite-sized pieces about 1 inch.
Bring a large pot of salted water to a boil. Work in batches to ensure no sticking. Boil gnocchi until tender for about 5 minutes. Drain well and set aside.
Heat olive oil in a large skillet over medium-high heat. Add gnocchi and cook until the exterior is golden brown, about 3 minutes per side. Also, do this in batches with none of the gnocchi touchings to ensure every gnocchi gets a crispy exterior.
Now time for the brown butter sage sauce. Make the sauce while crisping the gnocchi. Cook the butter in a medium skillet over medium-high heat until the butter begins to brown. This should be done in a light-colored pan to see the color of the butter and ensure the butter doesn't burn. It should take about 4 minutes to brown the butter.
Add the sage, salt, and pepper to the sauce. Take the pan off the heat.
Add gnocchi to the sauce and toss. Top with some fresh parmesan!