Preheat your oven to 180 degrees celsius (fan-forced) and line two baking trays with baking paper.
Place the butter and caster sugar into your Thermomix bowl and mix for 30 seconds, speed 3.
Scrape down the sides of the bowl and mix for a further 30 seconds, speed 3.5.
Scrape down the sides of the bowl and add the milk, vanilla extract, self raising flour and custard powder. Mix for 10 seconds, speed 3.
Scrape down the sides of the bowl and mix for a further 10 seconds, speed 3 until the dough comes together.
Roll heaped tablespoons of the mixture into balls and place them onto the baking trays.
Use the end of a wooden spoon or you knuckle to make an indent in the centre of the balls.
Fill each hole with a little bit of raspberry jam.
Place the baking trays into the oven and bake for 12 minutes.
Carefully remove the trays from the oven and allow the Jam Drops to cool on the trays for 5 minutes before carefully transferring to a wire rack to cool completely