Purée blackberries in blender then press contents through a mesh strainer or sieve to separate pulp from seeds. Discard seeds then combine purée with sugar in a small saucepan over medium heat. Stir frequently, letting the mixture cook for about 10 minutes until thickened. Set aside.
Combine vodka, amaretto, lemon-lime soda and the juice of two whole oranges in a cocktail shaker with ice. Stir until ingredients are combined completely then set aside.
Fill syringes with blackberry simple syrup then strain the alcohol mixture into glasses filled with ice. Squirt a tiny bit of the purée from the syringe then place the syringe inside glass. Serve immediately.
Notes
If you want a lighter version of this drink, use diet lemon-lime soda instead of regular. You can also substitute with club soda…cheers!