Preheat oven to 350 degrees F. Bring a large pot of salted water to boil. Cook gnocchi according to package instructions. Drain and set aside.

In a large skillet, cook sausage over medium high heat for 8-10 minutes or until thoroughly cooked, stirring frequently; drain and set aside. Place skillet back on the heat and cook the kale for 5 minutes, or until tender. Pour sausage back in the skillet.

In a saucepan over medium heat, melt the butter. Stir in garlic and cook until lightly golden, about 1 minute. Whisk in flour until mixture thickens. Add the milk and whisk until the sauce thickens, about 3 minutes. Whisk in the pesto and 1/2 cup of the cheese. Whisk until smooth. Season with salt and black pepper, to taste.

Spray a 9 x 13-inch baking dish with nonstick spray. Combine the gnocchi, sausage, and kale and pour into prepared pan. Pour the sauce evenly over gnocchi. Sprinkle with remaining mozzarella cheese and parmesan cheese. Cover with aluminum foil and bake for 25 minutes. Remove foil and bake for an additional 5 minutes, or until cheese is melted and gnocchi is bubbling. Let sit for 5 minutes. Serve warm.