You can substitute other flavorings for the vanilla in the brownies and/or ganache. Try ¼ teaspoon of extracts like raspberry, mint, or Fiori di Sicilia (a vanilla orange extract), or add a 1 to 2 tablespoons of bourbon, rum, or Kahlua for a boozy kick (just remember they'll be an adults-only treat then if you make the change in the ganache).