Preheat the oven to 360F. Pour cream into a saucepan and add butter. On low heat, wait until the butter dissolves, stir with a spatula until the two ingredients are combined. Add chopped garlic, as well as salt and spices to the saucepan, mix. After 2 minutes, add grated parmesan to the sauce, stir and cook for another five minutes. Set aside to cool a bit.
In a separate bowl, mix the ricotta, grated mozzarella (one cup), thawed and squeezed spinach. Gently mix with a spatula until it is combined well.
Grease the baking dish with a little non stick spray. Spread just a bit of alfredo sauce on the bottom, and put slices of zucchini on top.
Brush the top of the zucchini with more alfredo sauce, then top with the ricotta, mozzarella, and spinach mixture.
Repeat the layer of zucchini, sauce, and spinach mixture on top. Make the last layer of zucchini and alfredo sauce topped with the remaining cup of cheese.
Bake for 20-25 minutes until the mozzarella is browned. During this time, the zucchini will have time to fully cook and become soft. Remove, allow to cool in pan for 10 minutes to solidify. Cut the lasagna into portions with a knife or spatula, serve hot or warm.