Combine first 4 ingredients in a small saucepan and bring to a simmer over low heat. Cook for 5 minutes. Turn off the heat, cover and let steep for 15 minutes. Strain out the solids and return the liquid to a clean saucepan over low heat. Add the cocoa powder and corn syrup and whisk until smooth. Simmer for 2 minutes. Turn off the heat, add the chopped chocolate and stir until melted. Cool to room temperature. May be covered and stored in the refrigerator for up to 1 week.

Drizzle over vanilla bean ice cream and garnish with mint