Place a shallow bowl of water along side a shallow bowl with 1/4 cup sugar in it. Dip 4 cocktail glasses in water, then sugar to rim glass.
Place 4 scoops peach sorbet in blender. Add 2 shots orange liqueur. Fill blender with Champagne to maximum fill line or up to 1-inch from top of blending pitcher. Place cover on blender tightly. Blend until smooth and pour into cocktail glasses, keeping an eye out not to wreck the pretty sugar rims. Garnish with a few raspberries and a sprig of mint and serve.