Prepare a muffin pan by lining with paper cupcake liners. Preheat the oven to 400 degrees.
Remove the stems and papery skins from the pichuberries and rinse them in cold water. There is a sticky film on the outer flesh that needs to be rinsed off. Dry the berries, cut into quarters and place on a baking sheet. Sprinkle the tablespoon of sugar over the top. Roast in a 400 degree oven for 10-12 minutes. Pour into a mesh strainer to drain the liquid off. Allow to cool.
Cream the butter and sugar together until light. Scrape down the sides of the mixing bowl..
Add the egg, sour cream (or yogurt) and vanilla and mix well.
Mix the flour, baking powder, and salt together and add to the creamed mixture.
Gently fold in the cooled pichuberries, raspberries and toasted coconut. Use a scoop to fill each cup to about ⅔. Sprinkle with crushed toasted coconut and bake in the oven for about 25 minutes until lightly golden brown on top.