
Add the instant coffee, collagen powder and inulin to a glass or jug. Pour over the boiling water and stir until fully dissolved.
Leave to cool, then chill in the fridge until cold (at least one hour), or add ice to speed this up.
In a separate bowl, add the cream and maple syrup. Whip until soft, pillowy peaks form (thick but still spoonable).
Fill a glass with ice and pour over the chilled coffee.
Spoon or gently pipe the whipped cream on top, then finish with a pinch of nutmeg if using. Serve immediately.