1 1/2 ounces pineapple juice
1/2 ounce vanilla syrup
9 of the blackberries, the juice and syrup in a cocktail shaker; muddle well.
Add the ice and shake vigorously for 30 seconds, then strain into a cocktail (martini) glass.
Garnish with the remaining 2 blackberries (one on each side of the rim, like alien ears).