Pulse the date(s) and peanut butter in the bowl of a food processor using an S-blade until there are no longer any large chunks of date(s) remaining. If not using peanut butter, pulse the date(s) and avocado before adding the Greek yogurt and the other remaining ingredients.
1 (23 grams) Medjool date, 6 tablespoons (96 grams) salted natural peanut butter
Add the avocado, Greek yogurt, cocoa powder, vanilla and if using, banana to the bowl of your food processor. Process until totally smooth and creamy. There shouldn't be any lumps remaining.
140 grams avocado, 1/2 cup + 2 tablespoons (150 grams) plain Greek, 1/3 cup (38 grams) Dutch-process cocoa powder, 1 1/2 teaspoons vanilla extract, 1 medium banana, 3 tablespoons coconut sugar
Add sweetener to taste. If it's too thick for your liking, add a little milk at a time until it's the desired consistency.
Spoon into a container and let chill for an hour in the refrigerator. Best enjoyed on the first day but will also be fine if prepared in the evening and eaten for lunch the next day. Garnish with peanuts and shaved chocolate, if desired.