Line an 8x8-inch square pan with aluminum foil or parchment paper. Spray the bottom with nonstick cooking spray.

Place the mango pulp and sugar together in a saucepan and cook over a very low heat, stirring often, until they form a very thick syrup. This can take anywhere from 30 minutes to an hour. When ready, the texture of the syrup should thickly coat the back of a spoon.

Once the syrup is thick, add the butter and cook, stirring, for 3 more minutes.

Remove from the heat and - whilst the syrup is hot, stir in the pectin.

Immediately pour the mixture into the pan.

Allow to cool to room temperature, then cover with foil and refrigerate overnight.

Once the candies are properly set, cut them into squares and dust with sugar if desired.