Spray and line a loaf tin with baking paper that comes over the sides of the tin for easy removal.
Preheat the oven to 180°C.
Place all ingredients except flour and chocolate into the Thermomix bowl and blend 20 sec/speed 8. Scrape down the lid and sides of the bowl and repeat.
Add flour and incorporate 22 sec/dough setting/interval. Finish combining with a spatula if there is any remaining flour.
Add the chocolate and stir through with a spatula. Scrape into the prepared tin and bake for 50 minutes. Check the centre is cooked using a skewer. It should only have some chocolate on it, as opposed to raw batter. Add 5 minutes more cooking time if needed.
Cool in the tin before slicing and serving with or without butter! Lashings of butter!