Preheat oven to 375℉.
Prepare rice according to package directions. Stir in 7 ounces pumpkin puree, ½ cup heavy cream, 2 tablespoons cubed butter, ½ teaspoon salt, and ½ teaspoon pepper. Mix well and set aside.
Heat 1 tablespoon olive oil in a large skillet over medium heat.
Add to skillet, 5 ounces spinach and 1 minced garlic glove. Cook 2 to 4 minutes or until wilted. Let cool completely and squeeze out excess moisture. Season with ¼ teaspoon salt and ¼ teaspoon pepper.
In a medium bowl, add 1 cup ricotta, 1 slightly beaten egg, and spinach mixture. Mix well.
In the same bowl, add 1 cup mozzarella cheese, ½ cup parmesan cheese, ½ teaspoon salt, and ½ teaspoon pepper. Mix well.
Spread half the rice mixture in the bottom of a greased square baking dish. Top with spinach mixture and remaining rice.
Sprinkle with 1 cup remaining mozzarella and ¼ cup remaining parmesan cheese.
Cover casserole with foil. Bake 30 minutes
Remove foil. Bake for an additional 15 to 20 minutes or until golden brown and bubbling. Cool for 5 minutes before serving.