01 - Place chopped white chocolate in a heatproof bowl.
02 - Combine heavy cream and unsalted butter in a small saucepan. Warm over medium heat until mixture just begins to simmer.
03 - Pour the hot cream and butter mixture over the white chocolate. Let stand for two minutes, then stir until smooth and glossy.
04 - Incorporate vanilla extract and a pinch of salt into the melted mixture. Mix thoroughly to combine.
05 - Divide the mixture evenly into three bowls. Color one portion with red gel food coloring and fold in crushed freeze-dried raspberries. Color the second portion with blue gel food coloring and fold in crushed freeze-dried blueberries. Leave the third portion plain for the white layer.
06 - Transfer all three bowls to the refrigerator for approximately 45 minutes, or until the mixture is firm enough to scoop.
07 - Using a small scoop or teaspoon, take 1/2 teaspoon from each of the three colored mixtures. Press the portions gently together and roll between your palms to form a tricolor ball. Repeat the process with remaining mixture.
08 - Roll each shaped truffle in white nonpareil sprinkles or sanding sugar for a festive exterior.
09 - Arrange the truffles on a parchment-lined baking sheet and refrigerate for 20 minutes or until set before serving.