In a pan, sauté the shallots in 1 tbsp of olive oil until translucent. Add zucchini and cover with water halfway. Simmer until soft.
Using a slotted spoon, transfer zucchini to a blender with the remaining olive oil. Blend into a smooth sauce (if sauce is too thick, add cooking water to desired consistency.) Season with salt and pepper. Cook the ravioli according to the package instructions and drain.
Toss the pasta with zucchini sauce, garnish with red pepper flakes, Parmigiano Reggiano, and walnuts, then serve.