Step 1
Combine flour eggs and salt in the bowl of a food processor; pulse until dough holds together. Transfer to a clean work surface and knead until smooth about 10 minutes. If dough feels too dry add water a little at a time and continue kneading. Wrap dough in plastic wrap and refrigerate for at least 30 minutes.
Step 2
Preheat the oven to 450 degrees F (230 degrees C). Line a baking sheet with aluminum foil.
Step 3
Wash pumpkin slice into 8 pieces and discard seeds. Transfer pumpkin slices to the prepared baking sheet and cover with another sheet of foil to create a steaming pouch.
Step 4
Cook pumpkin in the preheated oven until tender about 30 minutes. Remove and let cool.
Step 5
While pumpkin is cooling heat oil in a small pan over medium heat. Add onion and sage; cook and stir until onion is soft and translucent about 5 minutes. Remove from heat.
Step 6
Scoop pumpkin flesh out of the skin and into a stand mixer. Add onion mixture and heavy cream; beat for a bit until mixture cools down. Mix in egg salt and pepper; set filling aside.
Step 7
Lightly flour a work surface. Remove pasta dough from the refrigerator and divide into 8 equal portions. Shape each portion into an oval-shaped flat disc. Run each disc through a pasta roller until it reaches the desired thickness and you have 8 long sheets of pasta. Lightly dust each sheet with flour.
Step 8
Lay one sheet of pasta on your work surface. Drop tablespoonfuls of filling for each ravioli evenly down the length of the sheet then lay a second sheet of pasta on top. Use your fingers to press down and seal the pasta around each bit of filling and cut ravioli with a pasta cutter or round glass. Repeat three more times with remaining 6 sheets of pasta and filling.
Step 9
Bring a large pot of lightly salted water to a boil. Cook ravioli in batches in the boiling water until tender yet firm to the bite 3 to 5 minutes per batch.
Step 9
Meanwhile heat butter and sage for sauce in a large saucepan over medium heat. Bring to a simmer and cook stirring frequently until butter is browned fragrant and foamy with brown bits in it 5 to 10 minutes. Be careful not to burn it. Season with salt and pepper. Add cooked ravioli to the sauce and sprinkle with Parmesan cheese.