To make the chocolate syrup, heat sugar, water, cocoa powder, and vanilla in a small saucepan until sugar dissolves, about 4-5 minutes. Pour into an airtight jar and let cool. Leftover syrup lasts up to a week at room temperature or 2 weeks in the fridge.
Sift together sugar and orange zest. Run an orange wedge around the rim of a glass, then dip and swirl the glass in the sugar mixture. Spoon chocolate syrup into the bottom of the glass.
To a shaker, add vanilla vodka, cherry juice, honey (if using and chocolate bitters. Add ice and shake until cold. Strain into glass and garnish with a fresh cherry.