Preheat oven to 400°F. Place butternut squash chunks onto a baking sheet, spray with olive oil spray and season with salt and pepper. Roast for ~30 mins until browned and tender. Let cool.
Put the squash into a bowl and mash. Add garlic and ricotta and fold until combined. Add lemon juice, nutmeg and salt. Put into a piping (or Ziploc) bag and cool completely.
Lightly flour the worksurface and lay 2 sheets of pasta next to each other. Pipe large blobs of the filling to create ~2” circles. Run a wet finger around the fillings. Lift the second sheet of pasta on top and gently mold around the fillings, trying not to leave any air bubbles inside. Use a 3” biscuit cutter to cut ravioli circles out and pinch seams. Filling should make ~15-18 raviolis.
Cook the ravioli for ~3-4 mins in a large pot of salted water. Scoop out with slotted spoon.
Melt the butter in a frying pan until dark brown and smelling nutty. Add the sage for 2 mins until crisp.
Spoon the ravioli onto plates and pour the butter and sage on top. Finish with parmesan.