Spread the coffee crispy base on one of the flourless sponge rounds and freeze until fully set, about 20 minutes.
Freeze the chai panna cotta in a 6-in/15-cm cake pan lined with plastic wrap. Remove from the pan and trim into a 5-in/13-cm round. Reserve in the freezer.
Place a 6-in/15-cm cake ring on a sheet pan lined with plastic wrap. Portion 8 oz/2