Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper for easy cleanup.
In a mixing bowl, combine chopped spinach, ricotta cheese, mozzarella cheese, parmesan cheese, breadcrumbs, garlic, salt, black pepper, and red pepper flakes. Mix well until combined.
Add the beaten egg into the mixture and stir until the egg is evenly distributed.
Using your hands, scoop out small portions of the mixture and form them into bite-sized balls or patties. Place them on the prepared baking sheet.
Bake in the preheated oven for about 20 minutes or until they are golden brown and crispy.
Remove from the oven and let them cool for a few minutes before serving. Enjoy your cheesy delights!