**Prepare the Cabbage**: Bring a large pot of salted water to a boil. Remove the core from the cabbage and carefully peel off 12-16 leaves. Blanch the leaves in boiling water for about 2-3 minutes until softened. Drain and set aside to cool.

**Make the Filling**: In a mixing bowl, combine ricotta cheese, mozzarella cheese, Parmesan cheese, egg, garlic powder, onion powder, salt, black pepper, red pepper flakes (if using), and parsley. Mix until well combined.

**Assemble the Dumplings**: Take one cabbage leaf and place a generous spoonful of the cheese filling at the base. Fold the sides over the filling and roll tightly from the base up to form a dumpling. Repeat with remaining leaves and filling.

**Cook the Dumplings**: In a large skillet, heat olive oil over medium heat. Add dumplings seam-side down and cook until golden brown, about 3-4 minutes on each side. You may need to do this in batches.

**Serve**: Serve hot, garnished with additional chopped parsley if desired. Enjoy your delicious cabbage dumplings!