Start by whipping heavy cream in a mixing bowl using an electric mixer on medium speed for about 3–5 minutes, until stiff peaks form. Transfer the whipped cream to the refrigerator to chill.

Brush a thin layer of maple syrup around the rim of your serving glass. Dip the wet rim into black sanding sugar and place the glass in the freezer for about 10 minutes.

In a blender, combine vanilla ice cream, milk, black cocoa powder, maple syrup, and vanilla extract. Blend on high speed for about 30 seconds until smooth.

Taste your black milkshake and adjust by adding an extra tablespoon of black cocoa powder if desired, then blend again.

Pour the black milkshake into the prepared glass, spoon the whipped cream on top, and garnish with sprinkles or extra sanding sugar before serving.