Making your own infused spirits and then sweetening into a liqueur or digestif gives control over the flavor and sweetness level. In this drink, a small glass at the end of a meal helps with digestion and would go well with a variety of desserts from chocolate-based ones to pecan pie.
Make the infused vodka: Combine the vodka, cacao nibs and coffee beans in a clean jar and seal. Shake, then infuse at room temperature, out of the sunlight, at least 4 days and up to 1 week. Strain the infused vodka through a fine-mesh sieve lined with cheesecloth or a coffee filter.
Make the simple syrup: Bring the brown sugar and 1/4 cup water to a simmer in a small saucepan over medium heat. Cook, stirring occasionally, until the sugar is dissolved, about 30 seconds. Remove from the heat and let cool.
Make the cocktail: Combine 1 1/2 ounces infused vodka with the Averna, bitters and 1/2 ounce of the simple syrup in a cocktail shaker with ice. Shake until frothy, then strain into a small glass.