Pat dry all sides of the chicken wings*. Set aside.
To make the rub: Place the fresh ginger, garlic, coconut sugar, soy sauce, and cayenne pepper into the insert of a slow cooker. Stir to incorporate all the ingredients.
Place the dried chicken wings into the insert of the slow cooker and toss to distribute the rub. At first, you might think that there is not enough rub, but as long as you make sure that all of the wings are coated thoroughly with the rub, you should be fine.
Cover and cook on low until all the fat from the chicken wings renders and the chicken is tender about 3-4 hours. If you can, stir once or twice during the cooking process.
Using a slotted spoon, remove the wings from the slow cooker onto a plate. Set it aside. Discard the liquid in the slow cooker.
Adjust the oven rack to the middle position. Place a sheet of parchment paper on the baking tray. Spray the wire rack with cooking spray and place on the prepared pan. Set it aside.
Preheat the broiler to high.
To make the glaze: Whisk together the water, tomato paste, coconut sugar, soy sauce, cayenne pepper, and ground ginger in a bowl.
Place the chicken wings, skin side up, in a single layer on the prepared wire rack.
Generously brush half of the sauce on top of the wings. Place the baking tray on the middle rack of the oven.
Broil until the wings are crisp with a light char, approximately 8 minutes. Watch carefully to avoid burning.
Using tongs, flip each wing and coat it with the remaining sauce. Continue to broil for 3-4 minutes until caramelized.
Top with toasted sesame seeds and green onions, if desired. Serve and enjoy!