Mix flour, cornstarch, salt, cayenne pepper, garlic powder, paprika and pepper in mixing bowl. Remove 1 cup flour mixture and place in shallow bowl; set aside.
Mix panko and rosemary in another shallow bowl, set aside.
Add cold beer to flour mixture in mixing bowl and whisk until well blended (should be thick like heavy cream).
Dredge cod filets in the reserved 1 cup flour mixture in shallow bowl; shake off excess. Dip cod into beer batter and dredge cod into panko mixture. Place fillets onto greased baking sheet; lightly spray fillets with cooking spray. Lightly season with salt and pepper.
Bake 15 minutes; until golden brown and fish is cooked through.
Serve and enjoy!
Notes
Fish and chips originated in Great Britain in the 19th century as a consequence of the rapid development of trawl fishing–pulling a fishing net through the water behind one or more boats.