Step 1

Heat oven to 400ºF.

Step 2

Combine the pork, lamb, beef, spinach, cheese, egg, basil, parsley, garlic powder, salt, red pepper flakes, and 1/4 cup of the bread crumbs in a large mixing bowl. Using your hands, mix until all ingredients are well incorporated. Use immediately or place in refrigerator for up to 24 hours.

Step 3

Place the remaining 1/4 cup of bread crumbs into a small bowl. Cover a scale with plastic wrap, weigh meatballs into 1 1/2-ounce (43-gram) portions, and place on a half-sheet pan. Using clean hands, shape the meatballs into rounds, roll in the breadcrumbs, and place in miniature muffin tin cups. Bake until golden and cooked through, about 20 minutes.