Preheat oven to 375˚F.
Place cauliflower pieces into a food processor and pulse until finely “riced”.
Place a skillet over medium heat and add oil.
Once skillet is hot add cauliflower and garlic and sauté for 2 to 3 minutes.
Transfer cauliflower mixture onto a clean piece of cheesecloth and squeeze as much liquid from the cauliflower as possible.
Transfer drained cauliflower to a mixing bowl and add Parmesan, cream cheese, egg yolks, and salt and pepper and stir until completely combined.
Cover and refrigerate for 1 hour.
Remove mixture from refrigerator and take ⅔ cup of the mixture and slightly flatten into your palm. Add 2 ounces of cheese into the center and completely seal cheese in the center and roll cauliflower mixture into a ball. Set aside and repeat until all the mixture and cheese have been used.
In a shallow baking dish combine the panko breadcrumbs and melted butter until well combined. Set aside.
Dredge each cheese stuffed ball into the flour until completely coated, (shaking off any excess), followed by the beaten eggs and finally into the panko breadcrumbs.
Lightly season each coated cauliflower ball with salt and place onto a lightly greased baking sheet, about 1 inch apart.
Bake the arancini for 20 to 25 minutes or until golden brown and cheese in the center of each ball has melted.
Remove from heat and serve with marinara sauce and more grated Parmesan, if desired. Serve.