• Preheat oven to 400 degrees F. Line a baking sheet with parchment paper.  Place the quartered butternut squash on the baking sheet and drizzle with the 2 tablespoons of olive oil.  Wrap tightly with foil and bake for 40-45 minutes, or until the squash is fork tender.  Remove from the oven and allow to cool for about 10 minutes.  Scoop out the pulp and add to the bowl of a food processor.  Puree the squash until it is uniformly smooth.  Measure out 2 cups worth of puree for the manicotti and reserve any remaining for another use. (See links below for ideas).
• In a medium bowl add the 2 cups of squash puree, 2 cups of fresh ricotta cheese, 2 eggs, 1/2 cup parmesan cheese and chopped sage.  Mix to combine.  Season with salt and pepper to your taste.  Set aside.

Crepes

• In a medium bowl, add the 3 eggs and break them up with a wooden spoon.  Stir in the water until combined (don't beat).  Sift in the flour and salt and stir until just combined.  Lumps are ok!  Force the mixture through a medium-meshed sieve into another bowl.  Brush an 8 inch nonstick skillet with butter and set over a medium-high heat.  Ladle 1/4 cup (I use the measuring cup) of batter into the skillet.  Tilt and rotate the skillet to evenly disperse the batter.  Cook for about 30 seconds then using a cake spatula, flip the crepe over and cook for another 15 seconds.  Invert onto a clean plate and repeat with the remaining batter to make 12 crepes in total and stacking them on top of each other.
• Preheat the oven to 425 degrees F.  Warm the marinara sauce slightly.  Add about 1/2 cup to the bottom of a 13x9 inch baking dish.  On a clean cutting board lay out a crepe and fill with 1/2 cup of squash mixture. Roll up leaving the ends open and place in the baking dish.  Repeat with remaining 11 crepes.  Pour 1 to 1 1/2 cups of sauce over the top of the manicotti.  Sprinkle with remaining parmesan cheese and cover tightly with foil.  Bake until bubbling and hot, about 15 to 20 minutes.