Meanwhile, if necessary, grate 1/4 cup Gouda cheese on the large holes of a box grater. Place 1 tablespoon smoked paprika, 1 teaspoon garlic powder, 1 teaspoon dried oregano, 1 teaspoon cayenne pepper, 1/2 teaspoon black pepper, 1/2 teaspoon packed light brown sugar, and remaining 1 teaspoon kosher salt in a medium bowl and stir to combine. Pat 1 1/2 pounds of catfish fillets dry with paper towels, then cut crosswise into 2- to 3-inch pieces.