Put finely chopped white chocolate in a bowl.
Heat cream in a small saucepan until it starts to simmer, just before boiling, and add to the chocolate, trying to cover as much as possible. But it won't cover completely.
Let stand 10 seconds and start to stir both ingredients together. The chocolate will start to melt.
Mix until well incorporated, smooth, and shiny.
If the chocolate does not melt completely, you can microwave the mixture (make sure you use a microwave-safe bowl) in 5-10 second spurts, mixing well after each time until the chocolate is completely melted.
Add the ground nuts, the rum and mix well.
Cover with plastic wrap and chill until firm, about 3 hours. Or freeze for about 1 hour. The mixture should be firm enough to make balls with it.
Scoop heaping teaspoons of the mixture, form into a ball with your palms, and roll in shredded coconut.
Chill, covered until ready to serve.
Store leftovers in the refrigerator in airtight containers with parchment paper between layers. Or in the freezer.