Heat oven to 400 degrees F.
Cut squash in half lengthwise, scoop out the seeds.
Add squash to a parchment lined baking sheet then drizzle both halves with olive oil, salt and pepper. Roast until tender and knife tip goes through easily, about 45-60 minutes.
Let it cool completely then scoop out the flesh and discard the skin.
Add ricotta, egg, 1/2 cup grated cheese, garlic, zest and squash into a food processor and pulse, just until mixed. You can also whip it all together by hand.
For assembly, cut pasta sheet in half, my package had 7 sheets yielding 14 cannelloni. Spread with a layer of filling, top with spinach leaves and then roll up placing them seam side down on a buttered baking dish.
For the sauce, melt butter in a sauce pan on medium until bubbly and golden brown, throw in all 10 sage leaves, let them sizzle and get crisp.
Take sauce off heat and squeeze in juice from 1/2 lemon.
Push sage to the side of the pan to reserve, spoon sauce on top of each shell and sprinkle each with grated parmesan or romano.
Loosely cover with foil and place in 400 oven until filling is cooked, around 15-30 minutes, depending on if dish has been refrigerated prior to baking.
Top cannelloni with warm sage leaves before serving. Serves 4-6