Preheat oven to 180 degrees celsius (fan forced) and grease and line a standard sized loaf tin.
Place the dates into the Thermomix bowl. Using the 2 second Turbo function, blitz 2 - 3 times to roughly chop.
Add the hot water and bi-carb soda and mix for 2 minutes and 30 seconds at 100 degrees, slowest speed (watch it carefully as it will bubble up in the bowl).
Add the butter and raw sugar and mix for 10 seconds, Speed 6.
Scrape down the sides of the bowl and allow the mixture to cool slightly.
Add the egg and mix for 5 seconds, speed 3.
Add the self-raising flour and plain flour and mix on 10 seconds, speed 5.
Scrape down the sides of the bowl and mix for a further 5 seconds on Speed 5.
Pour the batter into the prepared loaf tin and bake for 45-50 minutes, or until a skewer inserted into the middle comes out clean.
If the loaf is browning too much, loosely place a sheet of foil over the top and continue baking.
Allow to cool for 20 minutes in the tin before turning onto a wire rack to cool completely.