In a small pan, toast sesame seeds over medium low heat for 5-10 minutes or until fragrant. Make sure to stir occasionally so that they toast evenly. Let cool completely.
Using an immersion blender, blend the sugar and black sesame seeds together until the sugar looks like grey, damp sand and there are no visible whole sesame seeds.
If you don’t have an immersion blender, a small food processor/stand blender or a spice grinder work instead. You can also try to find black sesame powder or ground black sesame seeds (they’re the same thing) in a Chinese grocery store.
The vodka is to help with the texture of the ice cream and not the flavor. You can omit if you need to.