In a bowl, combine the ricotta, spinach, shallot, egg and lemon zest. Season with salt and pepper.
Line a baking sheet with parchment or wax paper. Arrange 10 wonton wrappers on a clean work surface. Top each with a rounded tsp. of filling. Moisten the edges with water and, working with 1 at a time, fold in half to form triangles; press down around the filling to seal. Transfer the ravioli to the prepared baking sheet in a single layer. Repeat with the remaining wrappers.
In a large pot of boiling, salted water, drop in the ravioli in 2 batches, letting the water return to a boil between batches. Cook until the ravioli bob to the surface, about 3 minutes per batch; strain.
In a large skillet, melt the butter over medium heat, swirling, until it browns and smells nutty, about 5 minutes. Turn off the heat immediately. Stir in the lemon juice, capers, and half of the parsley; season.
Divide the ravioli among 4 plates, drizzle with the butter sauce and top with the remaining parsley.