Preheat oven to 375°F.
Spray a baking sheet with cooking spray. Set aside.
Place flour, garlic powder, onion powder, salt and pepper in a large bowl. Mix well.
In another large bowl, add Panko, paprika and red pepper
In a third large bowl, add egg and lemon juice. Whisk to mix well.
Pat fillets with a paper towel.
Place 1 fillet in the flour mixture and dredge to coat completely.
Move to the egg mixture and turn to fully coat.
Remove from egg mixture, allowing excess to drip off, and place in Panko mixture. Turn and press gently to bread completely.
Place fillet on prepared baking sheet.
Repeat with remaining cod fillets until done.
Place baking sheet in preheated oven and bake for 30 minutes, turning over halfway through baking.
While fish is cooking, toast insides of buns in a toaster oven or in a dry skillet on the stovetop. Set aside.
Check fish for doneness and remove from oven when done.
Place a fish piece on the bottom of each bun.
Top with a dollop of tartar sauce and a small handful of shredded lettuce.
Place the top bun on and serve immediately.