Step 1: Prepare your spinach. If using fresh, blanch in boiling water for 1-2 minutes, then immediately transfer to an ice bath. Squeeze out all excess water using a clean kitchen towel or cheesecloth. If using frozen, thaw completely and squeeze out all excess water until it is very dry. Finely chop the dry spinach.
Step 2: In a large mixing bowl, combine the finely chopped, dry spinach, minced garlic, 1/2 cup grated Parmesan cheese, ricotta cheese, beaten egg, salt, black pepper, and nutmeg (if using). Mix well until all ingredients are evenly incorporated.
Step 3: Gently fold in 1/2 cup of the panko breadcrumbs into the spinach mixture until just combined. The mixture should be firm enough to handle and roll.
Step 4: Place the remaining 1/2 cup of panko breadcrumbs in a shallow dish. Using a small cookie scoop or your hands, roll the spinach mixture into approximately 1-inch balls. Roll each ball in the panko breadcrumbs until it is evenly coated on all sides.
Step 5: Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper. Arrange the coated spinach balls on the prepared baking sheet, ensuring there is a small space between each ball. Optionally, lightly mist the tops of the balls with olive oil spray for extra crispiness.
Step 6: Bake for 20-25 minutes, or until the spinach balls are golden brown and crispy on the outside. The internal temperature should reach 165°F (74°C).
Step 7: Remove from the oven and let cool for a few minutes before serving. Serve warm with your favorite dipping sauce like marinara or ranch.