Pat chicken thighs dry with a paper towel, then cut into ¼” thick strips. Place chicken in a large bowl and season with salt and black pepper, then cover with plastic wrap and let sit.
In a large bowl, whisk together 1 ½ cups buttermilk, 3 large eggs, and 1 tbsp hot sauce. In a second large bowl, whisk together 3 cups all-purpose flour, 3 tsp salt, and 2 tsp garlic powder.
Place a wire rack on a rimmed baking sheet, then begin coating chicken in the marinade. Dip each piece of chicken first in the flour mixture, then in the buttermilk, then again in the flour mixture, shaking off any excess. Transfer to the wire rack, then repeat until all chicken strips are coated.
Fill a large heavy bottom pot with oil until it’s about 2” high. Heat over medium-high until oil reaches about 350 F. You want to cook the chicken around ~325F, but the temperature will drop when you add the chicken. If you have a oil fryer use that instead.
When oil is hot, carefully add about pieces of chicken, depending on the size of your pan, and cook, turning every 1-2 minutes, until all chicken is a golden brown color and has an internal temperature of 160 F, about 6-7 minutes per batch. Transfer chicken to a clean wire rack, then repeat cooking remaining chicken.