Place all the ingredients in a Thermomix. Blend for 2 minutes or until completely smooth. Pass through a chinoise into a clean bowl. Pour into a 1 litre iSi canister and charge with 3 CO2 cartridges and shake well.
To cook the sponges we use a 1000W microwave. Use a small knife to punch 5 holes in the bottom of each cup.
Fill the first cup to a third of the way up, place in the