Step 1

Pre-heat the oven to 180C / 360F. Line a 9-inch square cake tin with baking paper. ensure there is enough to overlap the sides to make it easy to lift out the slice later.

Step 2

Place the Weetbix crumbs, flour, baking powder, cocoa powder, desiccated coconut and brown sugar into the Thermomix bowl. Mix for 10 seconds / speed Set aside.

Step 3

Add the butter, golden syrup and vanilla extract to the bowl. Melt for 3 minutes / 60 degrees / speed 2.

Step 4

Return the dry ingredients to the bowl. Mix for 10 seconds / speed 4.

Step 5

Scrape down the bowl and repeat: 10 seconds / speed 4.

Step 6

Tip the mixture into your lined baking tray. Use a spoon to press the mixture into the tin and smooth over the surface.

Step 7

Bake in the oven for 15 minutes.

Step 8

Remove from the oven and leave to cool completely in the tin.

Step 9

Add the icing sugar and cocoa powder to the Thermomix bowl. Mix for 5 seconds / speed 9.

Step 10

Add the butter and boiling water to the bowl. Mix for 20 seconds / speed 5.

Step 11

Scrape down the bowl and repeat: 10 seconds / speed 5.

Step 12

Spread the icing over the cooled slice and use a spatula to smooth it down, ensuring you cover the slice evenly and completely.

Step 13

Sprinkle over the desiccated coconut then transfer to the fridge and leave to cool for 30 minutes.

Step 14

Use the baking paper to lift the slice out of the tin. Use a sharp knife to cut the slice into 16 equal portions.