Preheat the oven 450F
Toss the sliced butternut squash in olive oil and place onto large baking sheet. Roast for about 30 minutes or until easily pierced with a fork.
While the squash roasts, prepare the pasta dough. Combine the flour, eggs, and egg yolk into a stand mixer and knead using the dough hook. Alternatively, can knead by hand. Knead until dough comes together into a ball.
Divide the ball in half, wrap in plastic wrap and allow to rest at room temperature for about 30 minutes. Pasta dough can be made ahead of time and refrigerated for up to 3 days.
Remove butternut squash from the oven and peel any remaining skin. Mash with a fork in a large mixing bowl.
Add in the ricotta cheese, parmesan, salt, pepper, and nutmeg and mix well using a wooden spoon (can also be done with paddle attachment on stand mixer). Set aside.
Remove dough from the plastic wrap and roll it out. We prefer doing this with the pasta attachment on our stand mixer (we use the #6 setting on our Kitchenaid attachment). The dough but can be rolled out by hand using a rolling pin as well, you just want to make sure you try to get it very thin.
Flour your ravioli mold, then lay the pasta sheet on top of the mold. Fill each ravioli with about 1 teaspoon of filling (depending on size of your ravioli mold). Brush edges of the sheet with the whisked egg. Lay a second pasta sheet on top and press using a rolling pin to close. Remove ravioli from the mold and place onto floured baking sheet. Repeat until you've used all of the filling.
In a large pot, heat up some lightly salted water to boil. Once the water boils, add in the ravioli and cook for 3-4 minutes.
While the water heats up, melt the butter in a large saucepan or skillet over medium heat. Allow butter to bubble and slowly brown.
Once the color changes, add garlic and cook for 2 minutes. Then, add salt, pepper, and fresh sage. Stir for about 1 minute, then toss in the cooked ravioli.
Toss the ravioli for 1-2 minutes until covered with brown butter. Serve with additional parmesan cheese.
