In a bowl, whisk soy sauce, honey, chili flakes, garlic cloves, ginger, sriracha and sesame oil together until combined.
Put the drumsticks in the slow cooker, pour the sauce on the drumsticks, cover and cook for 3-4 hours on high. Flip half way through.
Once cooked, take the drumsticks out.
Mix cornstarch and water in a bowl and pour it in the sauce. Stir and cover. Cook for 30 minutes on high.
Serve honey garlic chicken with white rice.