Defrost the cod and cut into strips (approx 1.5" - 2").
Mix flour, baking powder and salt in medium bowl.
Place 1/2 cup or so of flour in a separate, shallow bowl.
Add the cold beer to the flour mixture right before you're ready to cook and whisk well until combined.
Dredge the cod pieces in the plain flour and then drop in the beer/flour mixture to coat. Set aside.
Heat approx 1" of olive oil in skillet on med-high on your stovetop.
Once oil is hot, drop in the coated pieces of cod.
Let cook approx 2 min per side, turning gently until done.
Serve immediately.