6 oz. dark brown sugar3½ oz. rolled oats4 oz. all-purpose flour½ tsp. baking powder½ tsp. freshly ground allspice½ tsp. freshly grated nutmeg1 tsp. kosher salt¼ cup unsalted butter, room temperature20 oz. frozen peach slicesCombine the sugar, oats, flour, baking powder, allspice, nutmeg and kosher salt in a large bowl. Add the butter; work it into the dry ingredients until a crumbly texture forms. Fold in the peach slices.Butter the cooker and cook on low for three hours.