Combine 1 oz. concentrated cider, rye, lemon juice, and maple syrup in a cocktail shaker with ice. Shake vigorously, and strain into a cocktail glass (with or without ice). Garnish with ginger slices or lemon rind. Serve immediately.
To make the cider reduction: In a medium saucepan, over high heat, boil 2 cups of apple cider until it has reduced by half to 1 cup, about 20 minutes. Cool over an ice bath until at room temperature.