In a large Punch Bowl or Pitcher...
Let the Frozen Raspberries thaw a bit, and mix with the Powdered Sugar.
Pour the Raspberry Schnapps and Raspberry Syrup over the Raspberries.
Let this sit for 20 minutes to come together.
Finally pour in the Erdinger Weißbier and Champagne/Sparkling wine.
Right before serving, add ice cubes.