Step 1

Place the two types of chocolate into two microwave-safe bowls, and microwave in 30 second intervals at 70% power, stirring after each time, until melted. It should take 3-4 intervals. Be very careful not to overheat the chocolate. Stop microwaving if only little bits of chocolate are left, as there should be enough residual heat to melt the rest.

Step 2

Spread the dark chocolate into a large rectangle on parchment paper or a silicone mat to your desired thickness. I like it about 1/4" thick.

Step 3

Drop the melted white chocolate in piles on top of the dark chocolate. Using the tip of a spoon or a butter knife, swirl the two together. If high peaks remain from swirling, drop the tray on the table a few times to flatten it together.

Step 4

Sprinkle on the chopped pistachios and freeze dried raspberries while the chocolate is still melted.

Step 5

Let the bark harden completely before breaking into squares. You can usually accomplish this by leaving it at room temperature for at least one hour, in the fridge for 20 minutes, or in the freezer for 5 minutes. Room temperature is best for preventing condensation.