Hazelnut caramel slice

What's not to like about a crisp chocolate-y base covered in caramel, hazelnuts and chocolate? It's made in three stages:

For the base
200 grams butter, chopped
50 grams cocoa
1 cup dark brown sugar
1 teaspoon vanilla essence
2 eggs, beaten
225 grams plain wholemeal flour

For the caramel topping
180 grams butter, chopped
110 grams caster sugar
2 tablespoons golden syrup
0.75 cup sweetened condensed milk *
185 grams hazelnuts, toasted

For the chocolate topping
200 grams dark chocolate
1 tablespoon vegetable oil

Base: Preheat oven to moderate-slow (around 150 degrees Celsius). Grease and line a 20 cm x 30 cm baking tray. Melt (base) butter and cocoa together, add sugar and stir until dissolved. Remove from heat, add vanilla essence, eggs and flour, mix well. Spread into baking tray and bake for 20 minutes. Cool.

Caramel topping: Combine butter, sugar, syrup and condensed milk in a saucepan. Stir over low heat until butter is melted. Increase heat to moderate and simmer about 13 minutes or until mixture is a dark caramel colour. Remove from heat and stir in hazelnuts.

To assemble: Spread caramel/nut filling evenly over the cooled base and refrigerate for at least 30 minutes until firm. Melt the chocolate and oil together. Spread over the caramel topping, refrigerate until set, and cut into squares or bars.

* this time I used Pandaroo sweetened condensed coconut milk, after stumbling across it in the supermarket. It worked really well!