Cook the squash. Add the cubed summer squash to a large skillet and cook, stirring occasionally, until tender. Use a fork to check the texture of the squash.
Cook the onion and combine. Add the chopped green onion and cook for approximately 3-5 minutes. Remove the squash and onion from the heat. Combine one egg and the heavy cream in a bowl.
Toss and prepare for baking. Add one cup of shredded cheddar cheese and the summer squash to the egg mixture and toss to combine. Transfer the mixture to an 8 inch round baking dish and top with the remaining ¼ cup of shredded cheddar cheese.
Sprinkle and bake. Sprinkle the pork rind mixture over top of the summer squash. Bake the casserole in the preheated oven for 20 minutes or until brown and bubbly.