Combine creme de cacao, vodka, and vanilla-flavored vodka in a cocktail shaker. Secure lid on shaker and shake vigorously.
Spread sugar onto a flat plate wider than your martini glasses. Run the orange wedge along the lip of each martini glass to assure it's moistened all the way around; dip martini glasses in sugar to coat.
Divide remaining ice between the martini glasses. Strain the cocktail into the glasses.