Bake or steam the butternut squash prior. Here's the fuss free method I use: place the squash over the steamer piece in the instant pot, and add a cup of water. Then set the pressure cook mode for 20-30 minutes, depending on the size of the vegetable (20 minutes will be enough for a squash up to 1kg/2 pounds weight). Alternatively you can bake it in a 200°C (390°F) preheated oven for 40-50 minutes or until fork tender. Cool down at room temperature.
Meanwhile bring to boil abundant salted water for the pasta.
Scoop the pulp out and weigh 300 grams (you can use the rest to make vegan Gnocchi, Ravioli or Soup).
Add the pulp with the remaining ingredients of the sauce to a food processor and blend until smooth.
Transfer the mixture in a large pan or wok and bring to a boil while stirring constantly to prevent lumps.
Cook your macaroni al dente or according to the package directions and then drain well.
Meanwhile Preheat the oven at 180°C (355°F).
Add the cooked macaroni into the pot with the sauce and toss it up until they are evenly covered in the cheesy sauce.
Transfer the macaroni and sauce to a 20x30 cm baking ceramic dish or tray, smooth down and top with abundant vegan grated cheese.
Bake for 25-30 minutes or until the topping turns golden brown and crispy.