Combine avocado, maple syrup, and peppermint extract in a food processor, and process until smooth. Place avocado mixture in an airtight container in the refrigerator to chill for at least 30 minutes, or until ready to make and serve shots.
Melt chocolate in the microwave for ~ 1-2 minutes, or until fully melted, and put walnuts in a food processor and pulse nuts until finely chopped. Combine walnuts and melted chocolate mixture in a bowl, and stir well until nuts are fully coated with chocolate.
Right before serving, layer avocado and walnut mixture in to 8 2-ounce shot glasses. Using a narrow spoon, place a layer of avocado mixture on the bottom of each shot glass, followed by a layer of walnuts/chocolate. Repeat with another layer of avocado and another layer of walnuts, followed by a final layer of avocado. Sprinkle cacao nibs on top to garnish, and serve right away.
Although it's tempting to make these shots ahead of time and stick them in the refrigerator, this will cause the melted chocolate to harden, making them hard to eat!
Grasshopper Pie Shots https://www.eastewart.com/recipes-and-nutrition/grasshopper-pie-shots/