Separate the egg white from the egg yolk. Add the sugar to the egg yolk and blend well with an electric mixer. Once the mixture becomes a light yellow then add the mascarpone and blend until smooth.
In another bowl, mix the egg whites until stiff peaks. Fold the egg whites into the egg yolk and mascarpone mixture. In another bowl, mix the heavy cream until cream is whipped. Fold the cream into the egg mixture.
Now you are ready to layer the tiramisu. Start with putting your square flexipat on the perforated baking sheet. Spread a small layer of cream mixure on the bottom of the flexipat. Dip biscuits into coffee one at a time and layer biscuits in an even layer to cover the bottom of the flexipat. You can break the biscuits for them to fit if needed. Now spread a generous layer of the cream mixture on top of the biscuits and repeat until the flexipat is full. Once you have filled it to the top, dust (using our sift and go) generously with cocoa powder.
Place in refrigerator to cool and set. It will be ready to enjoy in about 45 minutes but you can make it in advance and serve it later if you would like. Using the biscuits will allow the tiramisu to last much longer.
