Heat 3-4" of oil to 350 F in a Dutch oven or deep fryer.
Place shrimp in a large bowl and season with 1/2 teaspoon Old Bay. Toss to coat.
In a medium bowl whisk together the flour, cornmeal, remaining Old Bay, garlic powder, onion powder and cumin.
In a shallow bowl or pie plate whisk together the eggs and buttermilk.
Add shrimp to the flour mixture and coat well. Shake off excess.
Dip shrimp in the egg mixture. Shake off excess.
Return shrimp to the flour mixture and coat well. Shake off excess.
Working in batches, fry the shrimp 3-4 minutes or until golden brown, turning once.
Remove to a paper towel-lined plate to drain.
If desired, sprinkle a bit more Old Bay over the shrimp before serving with your favorite cocktail sauce.