Place the chilled heavy cream, vanilla extract, and sugar into a large mixing bowl. Using an electric mixer, start whipping on low speed, gradually increasing to high. Whip until stiff peaks form — when you lift the beaters, the cream should hold a firm point but still look smooth and glossy. If it starts looking grainy or chunky, you've over-whipped and there's no fixing it, so stop and check often.

Line a 9-inch round cake pan with parchment paper, or use a flat serving plate. Spread a thin layer of whipped cream on the base to anchor the first layer of cookies.

Arrange a layer of chocolate wafer cookies on top, slightly overlapping if necessary, then gently spread approximately 1/3 cup of whipped cream over the cookies, ensuring full coverage. Continue layering cookies and cream, finishing with a final layer of whipped cream.

Once assembled, cover the cake tightly with plastic wrap, pressing it gently against the surface to prevent the cream from drying out. Refrigerate for at least 4 hours, or ideally overnight (8-12 hours). The cake is at its best after a full overnight rest.

For serving, uncover the cake and, if desired, garnish with chocolate shavings or fresh berries for added visual appeal. Slice with a sharp knife dipped in hot water and wiped dry between each cut for the cleanest portions.