Pre-heat the oven to 175°C (350°F) and line a baking tin with grease-proof paper.
Beat the butter, vanilla and sugar together until nice and fluffy.
Add the flour and mix until a dough forms.
Place the dough in the fridge for around 15 minutes to firm up a little.
Roll into small balls and press your thumb down in each one making a nice, fairly thick hole.
Bake for around 10 minutes, just until the edges begin to brown (they will look pale and be very soft to the touch - don't overbake).
Remove from the oven. You will probably find the holes have closed up a little when baking, so just use the back of a small spoon (or similar) to press the cookie down and make the holes larger again.
Leave to cool on the tray for around ten minutes and then transfer to a wire rack to cool completely.
Using a small spoon, carefully add the caramel, just until it reaches the top of the hole.
Melt the chocolate and then drizzle over the cookies. Enjoy!