Spray Slow Cooker with cooking spray
Whisk together all the sauce ingredients EXCEPT the cornstarch and water.
For chicken, use a sharp knife to cut through two wing joints, discard wing tips.
Salt and pepper the chicken wings and place them in the prepared slow cooker.
Pour tangy cranberry mixture over top.
Cook on low for 3 - 4 hours.
Before serving, remove wings from the slow cooker and place them on a baking sheet.
Transfer cooking juices to a skillet, skim any fat.
Bring juices to a boil, cook until mixture is reduced by half, 15-20 minutes, stirring occasionally. Mix cornstarch and water until smooth; stir into juices.
Return to a boil, stirring constantly; cook and stir until thickened, 1-2 minutes.
Broil wings until lightly browned, 2-3 minutes.
Brush with glaze and put back in the oven for 1-2 minutes.
Garnish with green onion if desired.
Serve with remaining Cranberry Horseradish for dipping.