Pat chicken thighs dry and sprinkle both sides with kosher salt.
Melt butter and mix it with Frank’s RedHot sauce in a small bowl.
Place chicken thighs in a bowl or container and pour the marinade over. Toss to coat well. Let marinate while the oven preheats (or up to 30 minutes for more flavor).
Place thighs on a parchment-lined or greased baking sheet. Bake for 25 minutes, or until the internal temperature reaches 165°F and the tops are starting to brown.