Step 1

Pre-heat oven to moderate (175 degrees celsius, fan-forced).

Step 2

Grease a slice tin (approx 28 x 18cm) and line with baking paper, leaving paper overhanging at sides to assist with removal of slice later.

Step 3

Cream butter and sugar until the mixture becomes a lighter colour.

Step 4

Add egg and beat again until well combined.

Step 5

Fold sifted flours, custard powder and salt into the mixture to form a dough.

Step 6

Press into tin, using a sheet of baking paper on top of the mixture and the back of a metal spoon to smooth out the mixture in the tin.

Step 7

Bake for 15-17 minutes or until a light golden colour.

Step 8

About 10 minutes before the base is ready to come out the oven, start making the topping by placing brown sugar, golden syrup and butter in a saucepan. Melt these ingredients over low heat and then bring to a simmer. Simmer for 3-5 minutes. (For a chewy topping, simmer more slowly and for less time. For a crunchier topping, simmer harder for longer.)

Step 9

Stir roughly chopped peanuts into the topping mixture.

Step 10

Once base comes out of the oven, pour topping mixture over base and spread out evenly.

Step 11

Return slice to the oven and bake for a further 5 minutes.

Step 12

Allow to cool before slicing into squares with a sharp knife.