01 - Combine raspberries, sugar, and lemon juice in a small saucepan. Cook over medium heat, stirring constantly, until raspberries 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 10.5 oz 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 melted and smooth. Remove from heat and incorporate vanilla extract along with 2 tablespoons of the cooled raspberry reduction. Reserve remaining reduction for alternative use.
03 - Cover the ganache mixture and refrigerate for 1–2 hours until sufficiently firm to scoop and shape without losing form.
04 - Line a baking sheet with parchment paper. Scoop 1-tablespoon portions of chilled ganache and roll into smooth, uniform balls. Arrange on prepared baking sheet and freeze for 30 minutes to firm before coating.
05 - Melt 5.25 oz white chocolate for coating. Using a fork, submerge each truffle in melted chocolate, allowing excess to drip off. Return to parchment paper and immediately sprinkle tops with crushed freeze-dried raspberries if desired.
06 - Refrigerate truffles until chocolate coating is completely set, approximately 20 minutes. Transfer to an airtight container and store chilled until serving.