Preheat the oven to 350°F (175°C) and grease a springform pan.

In a bowl, mix graham cracker crumbs, melted butter, and granulated sugar until combined. Press into the bottom of the pan and bake for 10 minutes. Allow to cool.

Melt dark chocolate in a double boiler or microwave until smooth; let cool slightly.

Whip heavy cream in a separate bowl until soft peaks form.

Beat eggs and granulated sugar until pale and fluffy; fold in melted chocolate followed by whipped cream.

Gently mix in half of the raspberries into the mousse.

Layer half of the mousse over the cooled crust, add remaining raspberries, then top with remaining mousse. Smooth the surface and refrigerate for at least four hours or overnight.