Preheat the oven to 400ºF. Cut the butternut squash in half (lengthwise) and remove the seeds. Place in a baking dish with the flesh side up and season with salt and pepper. Bake for 45 - 50 minutes.
To make the pasta dough:
Measure out the flour and add it to a food processor. Add the salt, psyllium husk and eggs and pulse until a thick dough forms. Stream in the water and continue to pulse until the dough comes together. Make sure not to over blend it - dough can get tough very easily.
Transfer the dough to a gluten-free floured surface. Knead with your hands until you have a soft, well-combined pasta dough. Cover with plastic wrap and let sit for at least 20 minutes.
To make the filling:
Once the squash is cooked, scoop it out into the food processor. Add the nutritional yeast and spices and process until almost smooth (you want a little texture left). Pulse in the spinach. Set aside.
To make the ravioli:
Using a rolling pin, roll your dough out on a flat surface until it's very thin. Less then 1/8" in thickness if possible. With the large sheet of rolled out the dough, cut out your ravioli using a 2" biscuit cutter (circle) or knife (square). Take one circle and add a 1/2 teaspoon of filling, wet the edges with your finger and top with another circle of dough. With a fork, pinch the edges together. Repeat with the remaining dough and filling.
To cook the ravioli:
Bring a saucepan of lightly salted water to boil. Carefully place the ravioli in the boiling water and cook for about 8 - 9 minutes (until the dough seems cooked through and they are floating at the top of your pan). Cook them in small batches at a time, about 5 - 6 to a pot.
To serve: top the ravioli with your sauce of choice (it's great with pesto, red sauce or plain old dairy-free butter), fresh herbs and crushed red pepper.