Preheat oven to 170°C and place a large baking dish filled with water onto the bottom shelf.
Place all ingredients into the Thermomix bowl in the order listed. Beat 10 sec/speed 6. Scrape down sides of bowl and repeat.
Pour into ungreased lasagne pan and bake 25-30 minutes until just set in the centre.
Remove from oven and cool completely before frosting with ganache.
Freeze into pieces that will fit into a lunch box and send to school or work frozen. They will be nice and fresh by morning tea time.
To make ganache, place 100g dark chocolate in pieces and 80g cream into Thermomix bowl and melt 5 min/50°C/speed 1. Stop and scrape down sides of bowl as needed. Spread equally across the cold cake. Refrigerate to set.