Rub chicken breasts with olive oil and place in the bottom of your slow cooker.
Whisk Honey Soy Sauce ingredients together in a medium bowl and pour HALF of the sauce over the chicken. Refrigerate the other half until later. Cook on low for 5-6 hours or on high for 3-4 hours or until chicken is tender enough to shred.
Remove chicken to a cutting board to shred. Meanwhile, strain any excess liquid from the slow cooker into a small saucepan. Whisk 2 tablespoons cornstarch with reserved refrigerated Honey Soy Sauce and add to saucepan. Bring to a boil then reduce to a simmer until thickened, stirring occasionally. Return shredded chicken to slow cooker and toss with thickened sauce.
*You can find hoisin sauce in the Asian section of your grocery store.