01 - Combine raspberries, sugar, and lemon juice in a small saucepan. Cook over medium heat, stirring constantly, until raspberries completely break down and mixture thickens, approximately 5-7 minutes. Press through a fine-mesh sieve to remove seeds. Allow to cool completely before proceeding.
02 - Place white chocolate, heavy cream, and butter in a heatproof bowl. Set over a pot of simmering water to create a double boiler. Stir continuously until completely melted and smooth. Remove from heat and incorporate vanilla extract along with 2 tablespoons of the cooled raspberry reduction, reserving remaining sauce for another use.
03 - Cover the chocolate mixture and refrigerate for 1-2 hours until firm enough to hold its shape when scooped.
04 - Line a baking sheet with parchment paper. Scoop chilled ganache using a tablespoon measure and quickly roll into balls between palms. Arrange on prepared baking sheet and freeze for 30 minutes to firm completely.
05 - Melt white chocolate for coating. Using a fork, dip each frozen truffle center into melted chocolate, allowing excess to drip off. Return to parchment-lined sheet and immediately sprinkle tops with crushed freeze-dried raspberries while chocolate remains wet.
06 - Refrigerate completed truffles until chocolate coating is fully set, approximately 20 minutes. Transfer to an airtight container and store refrigerated until serving.