Line a baking sheet with parchment paper. Melt dark chocolate in a double broiler, or in 30 second intervals in the microwave. Once melted, spread a thin layer over the baking sheet. Melt the white chocolate and drizzle all over the dark chocolate. Sprinkle with Craisins, Nuts and anything else you’d like. Put in a cool place and let set up for a few hours. Once hardened, break apart and serve.