Add freeze dried raspberries to the food processor and pulse to make a powder. Set aside.
Add heavy cream to a small sauce pan on medium heat and simmer over low heat or microwave for 1 minute, until hot and boiling.
When heavy cream just starts to boil, remove it from heat and stir in butter until fully combined and smooth. If the mixture has small lumps and you can microwave if for only 20 seconds, but not more, as you don't want to fully melt the butter.
Stir in the raspberry powder. Set aside to come to room temperature.
Add chopped white chocolate to a microwave safe bowl, and microwave on high in 20 seconds intervals until chocolate is melted. Stir very well after each interval to make sure the chocolate doesn't overheat and become unusable. You may need 2-3 intervals of 20 seconds for the chocolate to fully melt. Use the residual heat from chocolate to melt any remaining small pieces of chocolate by stirring well. Set aside for the chocolate to cool off to room temperature.
Add melted white chocolate to the butter mixture and stir well to combine. Cover with plastic wrap and place in the fridge for 1-2 hours. While the mixture is cooling in the fridge stir it a few times so the fat from the butter doesn't separate on top. Make sure you stir it often especially during the first 30 minutes, otherwise the butter will separate and harden.
Remove mixture from fridge, let it come to room temperature so its easy to work with.
Using a small ice cream scoop or a measuring spoon, scoop the mixture and roll into balls, roll into powdered sugar and place on waxed paper. Repeat the process.
If the truffles stick to your hand, dust your hands with powdered sugar.
Truffles can be stored in an airtight container in the fridge for 7-10 days. Or they can be frozen for longer storage for 2-3 months.
Don't store truffles at room temperature as they will lose their shape, or melt due to the high butter content.