Brown Sugar Syrup:
Heat 1 pint of water to boil in a small sauce pot. When boiling, add 1 pint compacted brown sugar and stir to dissolve. Let cool.
In a shaker, add mint, lemon, and brown sugar syrup. Muddle without shredding mint. Add Bourbon and ice. Shake. Strain over crushed ice in a rocks glass. Garnish with a mint sprig.