Begin by cutting the chicken. In a large bowl, coat the chicken evenly with buttermilk before covering it with plastic wrap and refrigerating it for at least one hour or overnight to allow the flavors to develop.

In a shallow dish, combine all-purpose flour with a blend of sweet Spanish paprika, kosher salt, poultry seasoning, ground black pepper, garlic powder, and Goya Sazonador seasoning. Add in the brown mustard and mix well.

Take the marinated chicken out of the refrigerator and let it sit at room temperature for about 10 minutes before heating a large pot or Dutch oven with oil to 375°F (190°C). Pat dry each chicken piece and evenly coat each one with the flour mixture, making sure to cover all sides.

Carefully place the coated chicken into the hot oil, skin side down. Fry for about 12-15 minutes, turning occasionally until golden brown and crispy, with an internal temperature of 165°F (74°C).

Let the chicken cool for a few minutes before serving it hot with your favorite sides, such as mashed potatoes.