In a saucepan over medium heat, bring ¼ cup cream, 1 stick unsalted butter, and ½ cup seedless raspberry jam to a simmer, stirring occasionally until butter and jam are melted.
Remove from heat and stir in chocolate until melted and smooth. Allow the residual heat to melt the chocolate. If needed to melt the last few lumps of chocolate you can return to low heat, but typically you don't need to.
Allow the mixture to cool for 10-20 minutes, until cooled significantly but not set.
(Optional) Add in 3 Tbsp of Chambord liqueur and mix well, until shiny. Adding the liqueur too early will cause the liqueur to evaporate or cook off faster. Note, if you omit this step, your drying times may be less.
Cover with a lid or plastic wrap and allow to set. Ideally overnight at room temperature, but you can also chill the mixture for 4+ hours.
On a parchment paper or sheet pan, portion out heaping 1 tsp balls (~1" diameter). Don't worry about shaping anything at this stage, it's fine if they're blobby.
Allow to dry uncovered in the fridge for 2-4 days. It's fine if the outsides get a little crusty. (The exact time may vary depending on your preferred texture, humidity of your area, etc.). To test, I simply shape a truffle like the remaining steps and taste test myself! If too soft/sticky, return to the fridge to continue to dry.
Take each blobby and roll it between your hands to form a ball. Residual heat from your hand should help melt that crusty exterior. It also will allow the cocoa powder to stick well.
Add each rolled ball to a dish of cocoa powder. I honestly, just drop it right in the cocoa powder container. You can use your fingers to coat the truffle, but I find that if I just kinda rattle the container in a circular motion, it coats easily with minimal mess.
Repeat with all remaining truffles until complete. Store dusted truffles in an airtight container for 1-2 days on the counter or up to a week in the fridge.