Preheat the oven to 400F. Add the olive oil to a cast iron skillet over high heat. Use a paper towel to pat the chicken thighs dry. Sprinkle with salt and pepper on both sides.
When the oil is hot, add the chicken thighs, skin-side down. Cook until the chicken skin is golden brown, about 5-7 minutes. Flip all the thighs over (so they are skin-side up). Add garlic powder, paprika, and brown sugar on top of each thigh.
Transfer the thighs to the oven and let them finish cooking for 7-15 minutes (depending on the size of the thighs), until the internal temperature reaches 165F.
Remove from the oven and let the thighs rest for 5 minutes. Dive in and enjoy!
