Prepare the Breading Station: In a shallow bowl, combine the flour, garlic powder, onion powder, paprika, salt, and black pepper. In another bowl, whisk the eggs. In a third bowl, mix the breadcrumbs, grated Parmesan cheese, and lemon zest.
Coat the Cod: Dip each piece of cod in the seasoned flour, shaking off the excess. Then, dip it into the beaten eggs, allowing any excess to drip off. Finally, coat the fish in the breadcrumb mixture, pressing gently to adhere.
Heat the Oil: In a large skillet, heat about ½ inch of vegetable oil over medium-high heat until it shimmers.
Fry the Cod Bites: Carefully place the breaded cod bites in the hot oil, cooking in batches to avoid overcrowding. Fry for about 3-4 minutes on each side, or until golden brown and cooked through. Remove with a slotted spoon and drain on paper towels.
Combine Ingredients: In a medium bowl, mix together the mayonnaise, sour cream, dill, chives, lemon juice, garlic powder, onion powder, salt, and pepper until well combined.
Chill: Refrigerate the dipping sauce for at least 30 minutes to allow the flavors to meld.