Bring cream to a boil in a small saucepan over medium-high heat. Remove from heat and stir in bourbon and vanilla.
Sprinkle chocolate over cream and allow to set without stirring for 5-6 minutes.
Meanwhile, pulse the pecans in a food processor until coarsely chopped. Add pound cake cubes and pulse until pecans and cake are finely chopped.
Stir the chocolate and cream until smooth. Pour the chocolate over the pound cake mixture in the food processor and pulse until combined. Transfer mixture to a medium bowl and refrigerate, stirring occasionally, until firm enough to scoop, about 1 hour.
Sift cocoa and powdered sugar together in medium bowl. Line rimmed baking sheet with parchment paper. Scoop out heaping tablespoons of bourbon-chocolate mixture and roll to form a ball. Roll ball around in cocoa-powdered sugar mixture to coat and transfer to baking sheet. Repeat with remaining bourbon-chocolate mixture. Refrigerate until firm, about 2 hours. These look great placed in mini paper muffin/candy cups.