Step 1: Prepare a baking sheet. Line a large baking sheet (approx. 10x15 inches) with parchment paper or a silicone baking mat. Set aside.
Step 2: Melt the chocolate. In a microwave-safe bowl, melt the chopped semi-sweet chocolate in 30-second intervals, stirring well after each, until smooth and fully melted. Alternatively, use a double boiler over simmering water, stirring until smooth.
Step 3: Stir in flavorings. Once the chocolate is completely smooth and melted, stir in the vanilla extract and salt until fully combined.
Step 4: Spread the chocolate. Pour the melted chocolate onto the prepared baking sheet. Use an offset spatula or the back of a spoon to spread it into an even layer, approximately 1/4 inch thick.
Step 5: Add toppings. Immediately and evenly sprinkle the dried cranberries, chopped pistachios, and crushed peppermint candies over the melted chocolate.
Step 6: Chill to set. Carefully transfer the baking sheet to the refrigerator and chill for at least 15-20 minutes, or until the chocolate is completely firm and snaps easily.
Step 7: Break into pieces. Once fully firm, remove the bark from the refrigerator. Break the chocolate bark into irregular pieces by hand or by carefully cutting with a large, sharp knife.