The easiest way to make the pasta dough is to use a big mixer with a dough hook, but it can also be made by hand. Combine all the pasta ingredients in a bowl and stir to blend. Add 1/2 cup of water and stir until all the flour is wet. If necessary, add no more than one Tbs. more water.
If using a mixer, mix the dough using the dough hook until it's uniformly smooth and damp. It should not be even a little sticky. If making the dough by hand, knead the dough on a clean countertop until smooth. Let the dough rest for about an hour.
Pull off a piece of dough about the size of a tennis ball. Run it through the pasta machine a couple of times at about the #6 thickness. Then go down to #3 for a couple of passes, and finally down to #2 once followed by one pass at #1--the thinnest. Dust the rolled pasta sheets with all-purpose flour and set aside, covered with a clean, damp cloth. Repeat until all the pasta is rolled. Extra pasta can be separated with plastic wrap, packed in a food storage bag, and either refrigerated or frozen.
To make the sauce, bring the whipping cream to a simmer in a small saucepan. Reduce it by about a third. Keep an eye on that pan! Cream can foam up like crazy!
Reserve a tablespoon of the butter, and whisk the rest into the reduced cream. Remove the pan from the heat and add the crabmeat. Stir very gently to mix the crabmeat with the cream sauce.
Heat the reserved tablespoon of butter in a medium skillet over medium-low heat until the butter bubbles. Add the green onions and cook until limp. Remove from the heat.
Add the crabmeat mixture, the cracker crumbs, and parmesan cheese to the skillet, and stir lightly with a spoon until all the ingredients are evenly distributed.
Move the crabmeat mixture into a bowl and refrigerate until distinctly cool.
To make the ravioli, place the bottom (metal) part of the ravioli form over a sheet of pasta, and with a knife cut all the way around. Make twelve sheets this way.
