Preheat your oven to 190 degrees celsius (fan-forced) and line am 18 x 28cm slice tin with baking paper - making sure to leave paper hanging over the sides.
Place the butter and golden syrup into your Thermomix bowl and cook for 3 minutes, 60 degrees, speed 2 to melt.
Add the remaining ingredients and mix for 12 seconds, speed 4.5 on reverse.
Scrape down the sides of the Thermomix bowl and mix for 10 seconds, speed 4, reverse to combine.
Tip the mixture into your prepared slice tray and press firmly with the back of a metal spoon to smooth the surface.
Place the slice into the oven and bake for 25 minutes or until golden brown.
Allow the slice to cool in the tin for 10 minutes before carefully transferring to a wire rack to completely cool.