Start by placing the freeze-dried raspberries into a food processor. Pulse until they turn into a fine powder. This helps color the truffles evenly and avoids a grainy texture.
Add the chopped white chocolate and butter to a microwave-safe bowl. Heat in short intervals, stirring each time, until fully melted and smooth. Gentle heat keeps the chocolate glossy and creamy.
Stir the raspberry powder and rosewater into the melted chocolate mixture. Mix slowly until everything is well combined and smooth. Cover the surface directly and refrigerate until firm.
Once chilled, scoop small portions and roll them gently into balls. Coat each truffle lightly in powdered sugar. If the mixture softens, chill again before continuing.