Pat the sliced pickles with paper towels to dry and set aside.
In a large bowl, combine the flour, cornmeal, garlic powder, paprika, salt, cayenne pepper, and black pepper.
Pour the buttermilk into a separate bowl.
Heat 1 1/2 inches of oil in a deep, heavy pot to 370 F (or use an electric deep fryer).
When the oil is hot, dip several slices of pickles in the buttermilk, then dredge in the flour and cornmeal mixture. Add several battered slices to the oil, but be careful not to crowd. Fry for 4 to 6 minutes, turning to brown on all sides. Use a slotted metal spoon or tongs to transfer the pickles to paper towels to drain. Repeat with the remaining pickles.
Serve with spicy mayonnaise, aioli, or ranch dressing.