In a medium saucepan, warm the cream over medium-low heat, stirring occasionally until steam begins to rise from the surface.
Meanwhile, place the 16 ounces of chocolate in a large glass bowl. When simmering, pour the cream over the chocolate, and shake gently to submerge the chocolate in liquid. Quickly cover the bowl with plastic wrap to retain heat, and let stand 10 minutes. Uncover and whisk the chocolate mixture until smooth.
Stir in the vanilla and salt, and pour into a 9 inch pie or cake pan. Cool for 15 minutes, then cover with plastic wrap and refrigerate 3 hours until completely set.
Line a rimmed baking sheet with parchment paper. Using a melon baller or spoon, scoop out truffles and place on the baking sheet. Refrigerate until set, about 15 minutes.
Meanwhile, pulse the freeze dried raspberries in a food processor until a fine dust is formed. (The seeds of the raspberries will remain, but you don’t need to worry about these because the raspberry dust will be distributed with a sieve. Be careful not to over-process, as the raspberry dust can become sticky from the pressure of the blades. A few pulses should do the trick!)
Create a double boiler by fitting a medium pot with a glass bowl. Fill the pot with a few inches of water, so that the bowl sits just above the surface of the water (not touching the water.) Place the remaining 10 ounces of chocolate in the bowl, and heat over medium low, stirring occasionally at first, then frequently until completely melted. (*Chocolate should be melted over fairly low heat so that it doesn’t turn gritty. The water touching the base of the bowl can cause your chocolate to overheat.)
Remove the truffles from the refrigerator and one by one dip into the chocolate with two spoons. Place back onto the parchment and sprinkle with raspberry dust (or topping of choice) using a small sieve.
Store in an airtight container in the refrigerator for up to two weeks.