Place ¼ cup corn starch in a shallow bowl and season lightly with salt and pepper. This will help the batter stick to the shrimp and add extra crunch.
In a separate bowl, mix the flour, the other ¼ cup corn starch, salt, beer, and baking powder together until a batter forms.
When ready to fry, add a few inches of vegetable oil to a pot set over high heat. Coat shrimp in cornstarch, salt, and pepper mixture and then dredge in the batter. Fry (in batches) for a couple of minutes - until golden and crispy.