Place ginger ale, soy sauce, brown sugar, garlic powder, and ginger in a bowl. Wisk to combine.
Add your fillets to the marinade and store in the refrigerator for 1 hour.
Remove your fillets from the marinade and pat them with a paper towel to dry.
Preheat your smoker to 225F and cook fillets for 45 minutes to an hour until an internal temp of 145F is reached.
Serve while hot, and enjoy!
Notes
Try a simple dry brine by combining 1 part of each sugar and kosher salt.
Cod is a mild-tasting fish, so it works like a blank canvas, meaning you can combine any kind of marinade ingredients for the brining process.
Before you smoke the cod, ensure you pat the cod fillets dry with paper towels to remove excess moisture once you remove the fish fillets from the brine mixture.