Preheat oven to 190 degrees (180 if using fan-forced). Line a 12 hole muffin tray with muffin liners.
Place bananas into the Thermomix bowl. Mash on Speed 8 for 10 seconds. Pour into a bowl and set aside.
Place the butter into the Thermomix bowl (don't worry about cleaning it) and melt on 100 degrees, 60 seconds, Speed 3. Scrape down the sides and melt for a further 30 seconds, 100 degrees, Speed 3 (if needed). Allow to cool slightly.
Add the vanilla extract, honey and milk and mix together on Speed 6 for 20 seconds. With the blades spinning on Speed 3, add the eggs one at a time through the MC hole.
Add the mashed bananas and mix for a further 20 seconds or until well combined.
Add the self-raising flour, caster sugar, baking powder, bi-carb soda, cinnamon and salt and mix for 5 seconds on Speed 4 (use the spatula to help mix).
Add the chocolate chips and mix on Reverse Speed 4 for 5-10 seconds or until just combined.
Divide mixture evenly between the muffin cases.
For crunchy topped muffins, sprinkle a little raw sugar over the top (optional).
Cook for 15 minutes or until they spring back when lightly touched in the middle.
Allow to cool in the tray for 5 minutes before transferring to a wire rack to cool completely.