Place the chicken tenders (or strips) in a large bowl.
Add 1 tsp cayenne, 1½ tsp garlic powder, ½ tsp onion powder, 1 tsp Cajun spice, 1 tsp oregano, 1 tsp salt, ½ tsp black pepper, and 300 ml buttermilk to the bowl; mix to coat the chicken evenly.
Cover and refrigerate the chicken to marinate for 4 hours.
While the chicken marinates, combine 2 cups all-purpose flour, 2 tsp paprika, 1 tsp cayenne, 1 tsp garlic powder, and 1 tsp salt in a large bowl and stir until evenly mixed.
After 4 hours, remove the chicken from the marinade, letting excess drip off, and dredge each piece thoroughly in the seasoned flour to coat.
Place the coated chicken on a plate and let rest at room temperature for 20 minutes to allow the coating to adhere.
Just before frying, dredge the rested chicken in the flour mixture once more for an extra-crispy crust.
Heat enough oil in a deep frying pan or Dutch oven to 350–375°F (176–190°C). Carefully add chicken and deep-fry about 2 minutes per side, or until golden brown and cooked through.
Transfer fried chicken to a plate lined with paper towels to drain excess oil.
Let the frying oil cool for 10 minutes, then combine 1 tbsp of the oil with 1 tsp cayenne and 1 tsp paprika in a small bowl; whisk and drizzle over the fried chicken before serving.