1.Preheat oven to 160°C. Grease a 20cm x 30cm rectangular slice pan; line base and long sides with baking paper, extending the paper 5cm over the sides.
2.Beat butter, sugar and egg yolk in a small bowl with an electric mixer until light and fluffy. Stir in sifted flours. Press mixture evenly over base of pan. Bake for 15 minutes.
3.Meanwhile, stir condensed milk, extra butter and syrup in a small saucepan, over medium heat, for 15 minutes or until mixture is golden brown. Working quickly, pour caramel over base; smooth surface with a spatula. Press peanuts into caramel with spatula. Bake for 10 minutes; cool.
4.Stir chocolate and oil in a small saucepan over low heat until smooth. Pour chocolate mixture over caramel. Refrigerate for 2 hours or until set before cutting into 40 pieces.
So what makes this slice worthy of a millionaire? It’s the ‘rich’ layering of the buttery shortbread base and sweet caramel filling smothered in chocolate, of course.