In a small saucepan over medium-high heat, add 1 cup of water, 1 cup of sugar, 1 1/2 cups of blackberries, two sprigs of rosemary, and 2 tsp of vanilla. Bring all of this to a boil, stirring occasionally, mashing the blackberries as you go. Once it comes to a boil, reduce the heat and simmer for another 5-8 minutes. Continue stirring and mashing the blackberries.

Place a strainer over a heat-proof bowl and pour the contents of the saucepan through the strainer. Use a rubber spatula to press all the juice out of the berries and then discard the pulp.

Cover the bowl with plastic wrap and place it in the fridge to cool. If you have a swing-top bottle you can pour it in there to keep. The syrup will be good for up to a month kept in the fridge.

In a cocktail shaker, measure out 2 oz of the vanilla blackberry & rosemary simple syrup, 1 1/2 oz of lemon juice, and 1 1/2 oz of rye whiskey. Add ice to the shaker, shake until chilled, and then strain the drink into a lowball glass with an ice sphere. Garnish with fresh blackberries and enjoy!