Easy Black Walnut Old Fashioned or Manhattan Cocktail

0 Rim the rocks glass. Add cacao nibs and sugar to a blender and pulse until cacao nibs are fine. Add the mixture to a cocktail rimmer. Wet the rim of your glass and place it gently into the cacao nib and sugar mixture to rim the glass. 
1 Build the cocktail. In a cocktail mixing glass, add in bourbon, chocolate whiskey and 6-8 dashes of black walnut bitters, then add ice. Note if you are making the Manhattan you will also add the vermouth during this step.
2 Stir. Stir the drink using a cocktail spoon and strain into a rocks glass over a large ice cube for an Old Fashioned or simply strain into a chilled coupe glass for a Manhattan.
3 Garnish. Garnish the old fashioned with a fresh orange peel & a cherry. If you're making the Manhattan, skip the orange peel & opt just for a cherry.