01 - Place 7 oz finely chopped white chocolate in a heatproof bowl.
02 - In a small saucepan, heat the heavy cream and butter over medium heat until just simmering, not boiling.
03 - Pour the hot cream mixture over the chopped chocolate. Let sit for 2 minutes, then stir gently until smooth and fully melted.
04 - Fold in the crushed freeze-dried raspberries until evenly distributed.
05 - Cover and chill the mixture in the refrigerator for at least 2 hours, or until firm enough to scoop.
06 - Using a small spoon or melon baller, scoop out portions and roll into balls with your hands. Place on a parchment-lined tray.
07 - Chill the rolled truffles for 15 minutes to firm up before coating.
08 - Dip each truffle in the melted white chocolate to coat, letting excess drip off. Return to the tray.
09 - While the coating is still tacky, dust each truffle with powdered sugar and, if desired, a sprinkle of raspberry powder.
10 - Let truffles set at room temperature until coating is firm, approximately 30 minutes.