Bruise the rosemary. Take each rosemary sprig and twist it gently between your hands a few times. This breaks up the leaves slightly and releases a lot more of the aromatic oils, so you get bigger rosemary flavor without needing more sprigs.
3 to 4 fresh rosemary sprigs
Make the rosemary vanilla syrup. In a small saucepan, combine the sugar, water, and bruised rosemary sprigs. Bring to a gentle simmer over medium heat, stirring occasionally until the sugar fully dissolves, about 3 to 5 minutes.
1 cup granulated sugar, 1 cup water, 3 to 4 fresh rosemary sprigs
Steep. Remove the saucepan from the heat and stir in the vanilla bean paste and sea salt. Let the rosemary sprigs steep in the syrup for at least 30 minutes. The longer it sits, the more rosemary flavor you'll get. Strain out the sprigs and transfer the syrup to a jar.
1 teaspoon vanilla bean paste, 1/8 teaspoon fine sea salt
Build the latte. In your mug, combine 2 tablespoons of the rosemary vanilla syrup with 2 shots of hot espresso and stir well.
2 shots espresso, 2 tablespoons rosemary vanilla syrup
Add milk. Pour in your steamed or warmed milk and give it a gentle stir. Top with foam if you like, garnish with a small sprig of rosemary, and serve right away.
6 to 8 oz steamed or warmed milk of choice