Steam the kale for 5 minutes. Drain and let in cool slightly.
Place the kale, anchovies, garlic, olive oil, cashews, and mascarpone in a blender, Nutribullet, or food processor. Process until smooth and creamy. You may need to add a little water to achieve the right consistency.
In the meantime, cook the ravioli according to the package instructions and drain. Place the ravioli in a large mixing bowl and pour the pesto on top. Toss the ravioli gently. Divide between the plates and garnish with some chopped cashews or grated Parmesan cheese.