- Preheat oven to 160* C (320* F) Fan.
- Grease a 23x33 cm baking pan and line with a sheet of parchment paper.
- In a mixer’s bowl, add the egg whites. Make sure the bowl is completely dry. Beat on high speed, until you create a meringue with soft peaks.
- Lower speed and add the icing sugar a little at a time. Beat until your meringue is soft and smooth.
- Spread evenly in baking pan.
- Bake for 8 minutes, until it turns a light golden. Then lower the oven temperature to 150* C (300* F) Fan and bake for another 15 minutes.
- When ready, remove from oven and carefully turn over onto another sheet of parchment paper that you have dusted with icing sugar. Set aside to cool.
For the cookie sheet:
- Turn oven temperature up to 180* C (350* F) Fan.
- Beat the butter and sugar in a mixer on high speed, until light and fluffy.
- Add the egg whites one at a time, until completely incorporated and the mixture becomes fluffy and smooth.
- Transfer to a baking pan lined with parchment paper. Spread evenly and as thin as possible.
- Bake for 4-5 minutes. When ready, remove from oven.
- Break cookie sheet into whatever shape you like with your hands.
For the caramelized walnuts:
- Melt the sugar in a small pan over low heat. At the same time, heat the walnuts in a microwave for 1 minute set at 700 watts, so that when you add them to the caramel they won’t make it harden quickly.
- When the sugar melts and turns to caramel, add the walnuts and stir to coat.
For the filling:
- Beat the heavy cream in a mixer on medium to high speed, until it becomes whipped cream. Add the coffee extract and vanilla extract.
- When the whipped cream becomes a shiny and thick, spread it along the length of the baked meringue.
- Sprinkle with some of the caramelized walnuts. Roll into a log. The meringue will crack in many places when you do this but it will look like a mosaic. Arrange the pieces of cookie sheet and caramelized walnuts over the top.