Heat olive oil in a large skillet over medium-high heat. Add spinach; cook until fully wilted, about 2 minutes. Cool, then squeeze spinach to remove as much liquid as possible.

Combine spinach, feta, and pine nuts in a blender or the bowl of a food processor; pulse until a fine paste consistency.

Drop 30 teaspoonfuls of filling onto 1 pasta sheet, spaced about 1 inch apart. Beat egg and water together in a small bowl; brush over remaining pasta sheet. Gently lay egg-washed pasta sheet, egg-washed-side down, over filled bottom layer, matching up the 2 sheets evenly. Press out air around each filling portion. Cut into individual ravioli. Press ravioli edges with the tines of a fork to seal.