Add all ingredients except the seltzer into a mixing glass with ice and stir well.
Strain into a Collins glass over ice.
Top with the seltzer and bitters.
Garnish with a lemon twist and pine sprig.
*Pine syrup: In a medium pot, add 1/4 cup roughly chopped conifer tips to 1 cup boiling water and 1 cup granulated sugar. Stir until sugar dissolves, remove heat and let cool for 30 minutes. Strain into a sealable container and refrigerate. Good for up to 2 weeks.