Preheat a fan-forced oven to 160C / 320F (180C / 355F for no fan). Line the bottom and side of a 22cm / 9-inch square baking tin with baking paper, leaving some overhang to easily lift and remove. Set aside.
Biscuit base - Add the flour, brown sugar coconut and melted butter to a large mixing bowl and use a spatula to mix until well combined and a dough forms.
Bake - Spread and press into the bottom of the baking tin as evenly as you can. Your hands should be ok, but you can use a lightly greased spatula as well. Bake for 12 minutes or until golden. Allow to cool while you make the caramel.
Lower oven temp - Lower oven temperature to 150C / 300F (170C / 340F for no fan).
Caramel Filling
Syrup - Add the butter, sugar and golden syrup to a large saucepan and place on medium heat. Gently stir until the mixture is melted and it begins to bubble around the sides.
Finish Caramel - Add the condensed milk and continuously stir until the mixture begins to bubble again. Continue stirring the bubbling mixture for exactly 5 minutes. It will darken slightly in color. Take off the heat and add the vanilla and salt and stir until combined.
Bake - Pour the mixture on top of the cooled biscuit base. Bake for 10 minutes. Once baked, allow to cool to room temperature, then chill in the fridge for 20 minutes or until just warm.
Chocolate
Add the cooking chocolate and oil to a heat proof bowl. Double Boiler: add on top of a pot of gently simmering water, making sure the bottom of the bowl isn’t touching the water and stir until melted. Microwave: microwave for 30 seconds at a time, stirring each time until smooth.
To Finish - pour on top of the cooled slice and spread evenly using a spoon or offset spatula. Allow to set in the fridge for 20 minutes.
How to get perfect clean slices - run a large knife under hot water and carefully dry with a towel. Slice into 4 x 4 bars, cleaning the knife, warming it and drying it with each slice. Serve.
Notes
Sweetened Condensed Milk - Use regular, full fat sweetened condensed milk for this recipe, not low-fat or skim.Storage - Caramel Slice can be stored in an airtight container for up to three days.Nutrition - is an approximate and is based on per slice.A note on measurements - this recipe is offered in weight measurements. This is in an effort to offer the most accurate way to get the best results. Cup measurements simply aren’t accurate enough for a recipe that needs precision and cup sizes differ depending on where you are in the world. Here is where you can learn more about how to measure ingredients using digital kitchen scales!