Line a 20cm round cake tin with baking paper and preheat your oven to 170 degrees fan-forced.
Place all of the cake ingredients into your Thermomix bowl and mix for 10 seconds, speed 4.
Scrape down the sides of your Thermomix bowl and mix for a further 10 seconds speed 4 or until the mixture is creamy and combined.
Transfer the cake mixture to your prepared cake tin and gently smooth the surface.
Bake for 25 - 30 minutes or until the cake is cooked when tested with a skewer.
Carefully remove the cake from the oven and prepare the cinnamon topping mixture by combining all of the ingredients into a small bowl.
Use a pastry brush to top the still warm cake with the cinnamon mixture. Let the cake sit in the cake tin for 10 minutes before carefully transferring to a wire tray to cool completely.