Place the mango flesh in a food processor or blender. Blend until completely smooth, scraping down the sides as needed. You want a silky, lump-free purée – no fibrous strings allowed. Set aside.

In a medium mixing bowl, combine the heavy cream and white sugar. Using an electric hand mixer or a whisk and some arm strength, whip until the mixture reaches a thick, yogurt-like consistency. Do not whip to stiff peaks – you want it to be thick but still fluid, like drinkable yogurt or melted ice cream. Over-whipped cream will make the popsicles dense and greasy.

Pour the mango purée into the whipped cream. Use a spatula to fold everything together gently until no white streaks remain and the mixture is uniformly orange. Don't stir aggressively – you want to keep the air you whipped into the cream. Transfer the mixture to a piping bag (or a zip-top bag with the corner snipped off).

Pipe the mixture into popsicle molds. Fill each mold to the top, then gently tap the mold against the counter a few times to release any air bubbles. Insert the popsicle sticks, add the lids (if your mold has them), and freeze for at least 4 hours, or until completely solid. Overnight is better.

When the popsicles are fully frozen, make the coating. Combine the dark chocolate and coconut oil in a microwave-safe bowl or in a bowl set over a pot of simmering water (double boiler method). Heat in 20-second bursts in the microwave, stirring between each, or stir constantly over the double boiler until the chocolate is completely melted and smooth. Do not overheat – chocolate seizes if it gets too hot. Let the mixture cool slightly for 2-3 minutes so it's warm but not hot.

Remove the popsicles from the freezer. Unmold them one at a time – if they're stuck, run the mold under warm water for a few seconds. Working quickly (the popsicles will start melting the moment they hit room temperature), hold a popsicle over the bowl of chocolate and spoon the chocolate over it, or dip it straight in if your bowl is deep enough. Let the excess drip off for a few seconds, then place the dipped popsicle on a parchment-lined tray or plate.

The chocolate will set in about one minute. Repeat with the remaining popsicles. If the chocolate starts to thicken as you work, reheat it gently for a few seconds.