Mix the flours, and salt with eggs, yolks, and water in the bowl of a stand mixer until the mixture comes together in a smooth dough, and springs back when pressed. Wrap the dough in plastic and refrigerate it for 20 minutes until needed.

Meanwhile, season the squash with oil, salt, pepper and thyme, then cook, covered in the oven for 20 minutes at 350 or until tender. Transfer the squash to the bowl of a food processor and blend until very smooth, then remove to a bowl, allow to cool and add the cheese, ginger and nutmeg.

Roll out the pasta to the thinnest setting on a pasta machine, then use the rim of a glass to cut out circles of dough. Make ravioli by wiping the bottom cirlce of dough with beaten egg, then filling with a heaping teaspoon of the filling, topping with another circle of dough, and pressing gently to remove air pockets and seal the edges. Dust the ravioli with semolina flour or cornmeal to prevent sticking, then refrigerate or freeze until needed.

To serve the dish, boil some lightly salted water for the ravioli and cook them until just al dente. Meanwhile, heat the 4 tablespoons of butter in a non-reactive saute pan until browned and aromatic, add the mushrooms and sage and cook until the mushrooms are completely cooked, about 5 minutes. Season the mixture to taste with salt and pepper, then deglaze with the wine and reduce by half. Add the chicken stock and reduce by half again, then add the spinach, finally finish by stirring in the remaining cold diced butter to make a creamy sauce. Add the ravioli and toss to coat, double check the seasoning and adjust if needed, then divide the ravioli evenly between 4 heated dinner plates and serve immediately topped with a little extra grated parmesan if desired.