Toss asparagus with olive oil, salt, and pepper on a rimmed baking sheet. Roast for about 10 minutes, or until softened and just beginning to brown, stirring halfway through cooking time. Remove from oven and cool slightly.
Transfer asparagus to large bowl. Add ricotta, parmesan, and salt; stir until well-combined.
Place one sheet of pasta onto a well-floured surface; brush with water. Drop filling onto the pasta by the teaspoonful, about 1 inch apart. Take a second sheet of pasta and place it on top of the first, carefully pressing to seal around filling. Use pasta cutter, knife, or pizza cutter to cut individual ravioli. Press along edges to make sure they are sealed. (For a visual tutorial, see this article on Allrecipes.com.)
Bring a large pot of salted water to a boil. Drop in ravioli, about 6 at a time, and cook for 3-4 minutes, or until they float to the top of the pot. Drain in a colander.
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