3 cups heavy cream
3 tablespoons sugar
1 tablespoon vanilla extract
2 (9-ounce) packages chocolate wafer cookies
Unsweetened cocoa (or chocolate shavings)
In a large bowl, beat cream, sugar and vanilla with an electric mixer on high speed until soft peaks form.
On a flat serving plate, arrange 7 cookies side by side in a circle, keeping 1 cookie in the center.
Spread with 1/2 cup whipped cream, making a 7-inch circle. Repeat with remaining cookies and cream, making 11 layers of cookies and ending with a layer of cream (there will be a few cookies left over). Cover with plastic wrap and refrigerate overnight.
To serve, dust top lightly with cocoa powder or chocolate shavings.