I am getting somewhat addicted to a new cocktail with Framboise (our raspberry infusion) and our newly released sparkling Riesling. I like the combination for the summer. The sparkling, being so sharp and low alcohol, blends very well with the high sugar, higher alcohol Framboise. I suspect that the sparkling Riesling would be a great cocktail base for all sort of liqueurs.
My recipe is 1/3 Framboise and 2/3 Sparkling but you should try for yourself and decide what you like.