Preheat your oven to 180 degrees celsius (fan-forced) and line two trays with baking paper.
Place softened butter along with the brown sugar into the bowl of an electric mixture and beat for approximately 8 minutes until pale and smooth.
Add 1 teaspoon of vanilla extract and the egg and mix to combine.
Add the self raising flour, plain flour and desiccated coconut and mix on a low speed until just combined.
Use a tablespoon to scoop up the mixture and gently roll into little balls before placing on the baking trays. Repeat until you have used all of the mixture.
Gently press down on the top of the balls with the back of a fork to flatten, before placing the baking trays into the oven to bake for 10 - 12 minutes.
Let the Monte Carlo Biscuits cool on the baking trays for 10 minutes before carefully transferring to a wire rack to cool completely.
To make the buttercream filling, place 60g of softened butter, ½ teaspoon of vanilla extract and the icing sugar mixture into the bowl of an electric mixer and beat for 3 - 4 minutes or until pale and combined.
Smear a teaspoon of the buttercream onto the back of one biscuit and a teaspoon of raspberry jam onto the back of another biscuit and sandwich together. Repeat until you have used all of the biscuits.
