Finely crush the freeze-dried raspberries into a powder using a food processor or by placing them in a sealed bag and crushing with a rolling pin until they reach a smooth, fine texture. Sift the powder through a fine-mesh strainer to remove any larger pieces and ensure a silky consistency. Set aside 2 teaspoons of the sifted powder for garnishing the finished truffles, and reserve the remaining powder for the ganache. While preparing this, cut the white chocolate and bittersweet chocolate into small, even pieces (about 1/4 inch) so they melt evenly, and ensure your butter is softened to room temperature.

Place the small pieces of white chocolate and softened butter into a heatproof bowl. Heat the heavy whipping cream in a saucepan over medium heat, stirring occasionally, until it reaches a gentle simmer (small bubbles will form around the edges). Pour the hot cream directly over the white chocolate and butter, then let the mixture sit undisturbed for 5 minutes to allow the residual heat to begin melting the chocolate. This resting period is crucial for achieving a smooth, glossy ganache without overworking it. After 5 minutes, stir gently with a whisk or spatula until the mixture is completely smooth and homogeneous.

Add the reserved raspberry powder to the white chocolate ganache mixture one tablespoon at a time, whisking thoroughly after each addition to ensure the powder is fully incorporated and the color is evenly distributed throughout. This gradual approach prevents clumping and creates a smooth, uniform pink ganache. Cover the bowl with plastic wrap and refrigerate for 2 hours until the mixture is firm enough to scoop into balls—it should hold its shape when pressed but still be soft enough to work with. I find that chilling in the coldest part of your fridge (usually the back) ensures even firming without the ganache becoming rock-hard.

Line a baking sheet with parchment paper. Using a 1-tablespoon measuring spoon or small ice cream scoop, carefully scoop the chilled ganache from Step 3 and gently push each portion onto the prepared baking sheet, spacing them about 1 inch apart. The ganache may be slightly sticky to work with, so lightly dampening the spoon between scoops helps prevent sticking. Once all portions are scooped, place the baking sheet into the freezer for 30-45 minutes until the ganache balls are completely firm and hold their shape, then transfer them to the refrigerator to await coating.

Place the chopped bittersweet chocolate in a heatproof bowl set over a pot of gently simmering water (creating a double boiler), ensuring the bottom of the bowl doesn't touch the water. Stir occasionally until the chocolate is completely melted and smooth, then remove from heat. I prefer using 70% cacao bittersweet chocolate because it has enough cocoa solids to balance the sweet ganache while maintaining a silky coating. Let the melted chocolate cool to approximately 85-90°F (about 29-32°C) before dipping, as chocolate at this temperature will coat smoothly and set with a glossy finish without clumping.

Working with one ganache ball at a time, use a fork to gently lower a truffle into the melted bittersweet chocolate from Step 5, turning to coat all sides evenly. Lift the truffle with the fork, tapping gently on the side of the bowl to remove excess chocolate, then carefully slide it onto a clean parchment-lined baking sheet. Immediately sprinkle the reserved 2 teaspoons of raspberry powder onto the wet chocolate coating while it's still tacky, allowing the powder to adhere beautifully. Continue this process with remaining ganache balls, working quickly so the chocolate coating doesn't set before you've garnished.

Allow the dipped and garnished truffles to set at room temperature for about 1 hour, or for a faster setting time, place them in the refrigerator for 15 minutes until the chocolate coating is completely firm and no longer tacky to the touch. The truffles are now ready to serve or store in an airtight container in a cool place for up to one week.