2. Fill one box at a time with the caster sugar and ensure all sides and the base have been lined. Pour any remaining sugar into the next box and repeat until all have been lined. Place in the fridge until required.
3. To make the cake batter, melt the butter, cocoa butter, honey and chocolate over a double boiler, set aside to cool slightly.
4. Whisk eggs and yolks together and warm them up by whisking continuously over a double boiler. Once they have begun to fluff up whisk until light and fluffy.
5. Form a meringue by whisking the egg whites and caster sugar to a stiff peak using a stand or hand mixer. Gently fold the warm chocolate into the fluffy egg yolk mixture then add the meringue.
6. Fill the greased moulds and cook in the preheated oven for 12 minutes. Remove from the oven and serve hot (still in the box) with a heavy dusting of matcha green tea powder on top.