In the bowl of an electric mixer fitted with the whisk attachment, combine the heavy cream, mascarpone, sugar, coffee liqueur, cocoa powder, espresso powder, and vanilla. Mix on low speed to combine and then slowly raise the speed, until it forms medium to firm peaks. If you whip them too firm then they won't soften the cookies as well. To assemble the cake, arrange cookies along the bottom of an 8" springform pan, filling in spaces by breaking cookies into pieces. Spread 1/3 of cream evenly over cookies then cover with another layer of cookies. Continue layering until you end with remaining cream. You can make up to 5 alternating layers if you like, you will just need more cookies and less cream between layers. Cover with plastic wrap and refrigerate overnight. I didn't have an 8" springform pan either, so I used my 9" springform pan. Worked perfectly fine.