In a high speed blender, combine the milk, cacao powder, maple syrup, vanilla, and peanut butter, if using, along with the ice.
Blend until the ice is totally pulverized, about 60 seconds. There should be no chunks of ice remaining. Taste and adjust any flavoring as needed. You can add more cacoa powder for a darker chocolate flavor, or more peanut butter for extra creaminess and richness.
Serve right away for the best texture. Top with whipped cream and chocolate shavings for an extra impressive look.
Notes
Nutrition information is for half the batch using store-bought almond milk, without any additional toppings. This information is automatically calculated, and is just an estimate not a guarantee, since it will vary drastically depending on the type of milk you use.If you have any leftovers, you can freeze them into an ice pop, for a cold treat later.