Bring a large pot of water to a boil, cook pasta according to package directions.
In a skillet sauté carrots with 1 tablespoon olive oil over high heat for three minutes, season with salt and pepper and set aside.
Meanwhile in a skillet sauté onion with 2 tablespoons olive oil for three minutes, add squash and broth, season with salt and pepper and bring to a simmer.
Simmer until squash is thoroughly cooked.
Let cool down and process 1/3 of squash mixture in the blender until smooth then add back to the skillet. Stir in carrots.
Drain pasta and toss with squash mixture, stir in marjoram leaves, top with walnuts and drizzle with remaining oil before serving.
