Start by chopping the chocolate into small pieces and placing it in a microwave-safe bowl. Heat in the microwave in 20-second intervals, stirring between each, until melted and smooth. Allow it to cool slightly.

In a separate large bowl, beat the heavy whipping cream using an electric mixer on medium speed. Gradually add in the powdered sugar and vanilla extract. Continue mixing until soft peaks form, which usually takes about 2-3 minutes.

Gently fold the cooled melted chocolate into the whipped cream mixture using a spatula. Be cautious not to deflate the cream; the goal is to maintain that airy texture.

In a small bowl, lightly mash the raspberries using the back of a fork. You should have a mix of whole and crushed berries for added texture.

In serving cups or bowls, add a layer of the chocolate mousse, followed by a layer of the mashed raspberries. Repeat until all ingredients are used up, finishing with a layer of chocolate mousse on top.

Place the mousse cups in the refrigerator for at least 2 hours, allowing them to set properly.

Just before serving, top with chocolate shavings or a few whole raspberries for a touch of elegance.