Australian Caramel Slice

Step 1: Preheat the oven to 180°C/350°F (fan 160°C).

Step 2: Grease and line a 28 x 18 cm (lamington pan) or 7 x 11-inch rectangular pan with baking or parchment paper. Leave an overhang to make the slice easier to remove.

Step 3: Mix the base ingredients together and press the mixture into the pan.

Tip: An egg flip can be used to press it down.

Step 4: Bake for 15 minutes, until the surface is golden. Cool in the refrigerator if you have time.

Step 5: Lower the oven temperature to 160°C/320°F (fan 140°C).

Step 6: Put the butter, sugar and vanilla in a saucepan over medium-low heat. Once the butter has melted, whisk to combine it with the sugar, then leave the mixture until it comes to a simmer.

Step 7: When bubbles appear, add the condensed milk. Whisk constantly for 5 minutes, until large, slow bubbles begin to appear on the base of the saucepan.

Tip: Small brown specks can form if the mixture is not stirred constantly. They do not affect the flavour.

Step 8: When bubbles begin to appear, whisk for 1 minute. Pour the caramel onto the base and tilt the pan to spread it evenly.

Step 9: Bake for 12 minutes. Splotchy brown patches can appear if the oven does not distribute heat evenly.

Step 10: Cool on the counter for 20 minutes, then refrigerate for 30 minutes. The bottom of the pan should still be warm, while the surface should feel cool, not cold, to the touch.

Step 11: Put the chocolate and oil in a microwave-safe bowl. Microwave in 30-second bursts, stirring between bursts, until the chocolate is fully melted.

Tip: The recipe gives 4 x 30 seconds as an example.

Step 12: Pour the chocolate over the caramel and spread it with a spatula. Gently shake the pan to level the surface.

Step 13: Refrigerate for 1 hour or until set. Remove from the refrigerator and leave out for 5 minutes to take the chill off the chocolate slightly. Cut into bars or squares to serve.