If making whipped cream, add the heavy cream to a bowl and whip at medium speed until it starts to thicken, then increase to high speed until peaks stand up straight. Place in the fridge.

To make a rim with black sanding sugar, pour sanding sugar into a shallow bowl. Brush some maple syrup on the rim of your glass and dip into the sanding sugar. Tap to remove excess sugar and place in the freezer for a few minutes.

In a blender, add vanilla ice cream, milk, black cocoa powder, maple syrup, and vanilla extract. Blend until totally combined and smooth. Adjust thickness by adding more milk if needed.

Taste and add more black cocoa if desired. Note that the milkshake may look dark grey initially but will become closer to black over time.

Top with whipped cream and add sprinkles if desired.