Fill a cocktail shaker with ice. Pour brandy, pear juice, lemon juice, and simple syrup over ice. Cover and shake vigorously for 1 minute. Strain and pour into a chilled martini glass. Garnish with sliced pear. Serve immediately.
Notes: To make simple syrup, cook 1/2 cup each sugar and water in a small pan over medium heat until sugar dissolves and mixture turns clear; cool before using. Can be kept, covered and chilled, for 6 months.