1 to 2 tbsp sugar (Depends on how sweet you like your mojitos. I like mine sweeter so I used 2 tbsp in mine, but Dan likes his a little more tart so I only put about 1.5 tbsp in his. Alternatively, you can use simple syrup, which will give you a more concentrated and uniform sweet flavor. I've been using that in all my cocktails lately and I think they are even more delicious this way. Just bring ½ cup sugar and 1 cup water to a simmer over medium-high heat, until sugar is completely dissolved. Allow syrup to cool, and then measure out however much you want to use for your drink. I suggest starting with ½ to 1 oz per drink and going from there.)
⅓ oz lime juice
2 oz club soda
Directions
In the bottom of your drinking glass, muddle/crush together blackberries, mint leaves, sugar/simple syrup, rum, and lime juice.
Add some ice cubes, then pour in club soda and stir.
Garnish with a few whole blackberries and a sprig of mint.
Enjoy immediately.
Recipe by Just Putzing Around the Kitchen at https://www.justputzing.com/2012/04/blackberry-mojitos.html