Special equipment: a 12-cup silicone mini muffin pan
Add the heavy cream to a small saucepan and warm it gently over medium heat until small bubbles form around the edges. Place the chopped chocolate in a medium bowl and pour the hot cream over the chocolate. Let sit for about 2 minutes, then stir with a whisk, working from the center of the bowl outwards, until the ganache mixture is smooth and well incorporated.
To a 12-cup silicone mini muffin pan, sprinkle 1/2 teaspoon Pop Rocks in each cup. Divide the ganache evenly among the cups and press the raspberries on top. Refrigerate until set, at least 2 hours.
Just before serving, unmold the tarts and sprinkle with a few of the gold stars.