Arrange the top rack of the oven to be about 5 inches from the top heating element, preheat oven to broil. Line a baking sheet with foil and lightly spray with non-stick cooking spray.
Place the chicken on the baking sheet and broil for 5 minutes on each side. Place the chicken in the slow cooker in an even layer. In a medium bowl whisk together the brown sugar, soy sauce, dry sherry, honey, ginger, garlic powder and onion powder. Pour over the chicken and cook on HIGH for 3 to 4 hours, LOW for 6 to 8 hours. Rotate the chicken halfway through, to make sure all are coated in the sauce.
Once chicken is done turn broiler on again. Place chicken on a foil lined baking sheet in an even layer.
Pour the sauce from the slow cooker into a small pot and bring it to a low boil. In a small dish combine the 2 tbsp corn starch and 2 tbsp water, stirring until smooth. Pour into the sauce in the pot and stir until sauce thickens. Brush the chicken with the sauce and broil for 2 minutes, flip chicken, brush with more sauce, and broil an additional 2 minutes.
Sprinkle with sesame seeds and sliced green onions for garnish. Enjoy!
*Feel free to substitute any type of chicken you would like! Chicken breast, chicken thighs, wings, etc. If using boneless skinless chicken breasts, you can skip the oven broiling parts of the recipe, and just shred the chicken when it's done cooking.