Add 2 large rosemary sprigs and lemon juice to a shaker and crush with a muddler (alternately you can crush them with your hand and then add to shaker). Let sit for 30 to 60 minutes for the flavors to develop (this step can be skipped if you don’t have time).

Add bourbon, maple syrup and ice to above the level of the liquid and shake vigorously for 15 seconds.

Strain mixture into rocks glasses filled with ice and garnish each with remaining rosemary sprigs.