Pulse the frozen candy bars in a food processor until broken into shards. Fold into the cooled chocolate mixture along with the cranberries. Spread over the bottom of a baking dish and smooth the top. Refrigerate about 2 hours, until firm.
Use a melon baller or small ice cream scoop to scoop out balls of the chocolate mixture; place them on a parchment or waxed paper lined baking sheet and set them aside for an hour or 2 to let them come to room temperature.
Melt the chocolate in the top of a double boiler and remove from the heat. Use a spoon to dip the truffles them into the liquid chocolate, then return them to the baking sheet. Use the spoon to drizzle a squiggle of chocolate over the tops. Chill until set.
In a saucepan, bring the cream just to a simmer over low heat. Pour the cream over the chocolate in a bowl and let stand about 10 minutes to melt the chocolate. Add the vanilla and stir until smooth. Set aside to cool for 1 hour at room temperature. Then beat the chocolate at medium speed until it gets thick and light colored. Spread over the bottom of a baking dish and smooth the top. Refrigerate about 2 hours, until firm.
Pour the cocoa powder onto a deep plate or shallow bowl. Use a melon baller or small ice cream scoop to scoop out balls of chocolate; place them on the plate with the cocoa powder and roll between 2 forks to completely coat with the cocoa powder. Then use the forks to carefully transfer them to a parchment or waxed paper lined baking sheet.