Preheat oven to 350 degrees. Lightly oil a small baking sheet. Place squash on small baking sheet, and season with salt and pepper. Bake until tender when pierced with the tip of a knife, about 45 minutes. Remove from oven, and let cool. Scoop out flesh, discarding skin. Transfer flesh to a damp cheesecloth-lined sieve set over a bowl. Refrigerate overnight.
Place ricotta cheese in a second damp cheesecloth-lined sieve set over a bowl. Refrigerate overnight.
Transfer squash to a large bowl. Pour squash liquid into a small saucepan, and place over medium-high heat. Cook until reduced and slightly thickened, 5 to 10 minutes. Add to squash. Season with salt and pepper. In a small bowl, stir to combine drained ricotta and creme fraiche. Stir into the squash mixture.
Prepare an ice bath; set aside. Bring a small pot of water to a boil. Add chives, and blanch for 15 seconds. Transfer to ice bath to cool. Drain well; set aside.
Working with one wrapper at a time and keeping the others covered with plastic wrap; lay wrapper on work surface with a long side facing you. Spread scant 1/4 cup of the squash mixture along one long edge, leaving a 3/4-inch border on either side. Roll up like a jelly roll to enclose filling, brushing edge with egg wash to seal. Tie each end closed with a chive. Repeat with remaining wrappers and filling.
Heat oil in a large skillet. Add cannelloni, and cook until heated through and evenly browned, about 1 1/2 minutes per side. Serve with Jerusalem artichoke vinaigrette, and garnish with shelled edamame, if desired.