Smash and peel the garlic cloves. Combine the apple cider, garlic cloves, brown sugar, allspice, salt and bay leaves in a large pot. Simmer on the stove top for 5 minutes, stirring often.
Take the brine off the stove top and add 4 cups ice water. Place the turkey breast in a 2 gallon zip lock bag. Add the brine to the bag adding water if needed to submerge the turkey. Close the bag and place in a pan. Refrigerate overnight.
After the turkey has brined overnight, drain the turkey and rinse. Take the softened butter and smear it under the skin of the turkey breast. Dry the turkey with paper towels. Season the turkey with salt and pepper.
Cook on the grill or in an oven at 325 degrees until the turkey reaches an internal temperature of 165 degrees, about 2 1/2 hours.
Let the turkey rest for 30 minutes, slice and serve.