Begin by marinating the chicken. In a large bowl, combine the buttermilk and chicken breasts. Ensure the chicken is well coated. Cover and refrigerate for at least 30 minutes or up to overnight for best results.
In another bowl, mix together the flour, garlic powder, onion powder, paprika, salt, black pepper, baking powder, and baking soda.
Heat the vegetable oil in a cast iron skillet or deep fryer over medium-high heat until it reaches 350°F (175°C).
Remove the chicken from the buttermilk, allowing any excess to drip off. Dredge each piece in the flour mixture, ensuring an even coating. Shake off any excess flour.
Carefully place the coated chicken in the hot oil. Fry for about 5-7 minutes on each side, or until golden brown and cooked through (internal temperature should reach 165°F/74°C). Remove and let drain on a paper towel-lined baking sheet.
While the chicken is frying, bake or warm the biscuits according to package instructions if using store-bought. If making biscuits from scratch, prepare and bake them beforehand.
To assemble the sandwiches, slice the biscuits in half. Place a piece of fried chicken on the bottom half, add lettuce and tomato if desired, and drizzle with honey or hot sauce. Place the top half of the biscuit over the chicken.
Serve hot and enjoy your Chicken Biscuit Sandwich!