The ice cream is a bit more of a trick. Soften it slightly and press some into a mold or cutter the size of the cakes. After filling, quickly lay on parchment, finishing the rest as fast as possible. Seal the container and put back in the freezer. Or, you can spread the ice cream into the thickness you prefer in a flat-bottomed plastic container or rectangular cake pan, seal and freeze, then cut into circles and refreeze again. Don’t cut at the time you are planning on serving them or they will melt before you get everything ready to go.