Preheat the oven to 180ºc/160ºc fan and line a 12 hole mini cake tin with parchment paper around the edges
Cream the butter and sugar together in a bowl
Add the plain flour and mix until you make a shortbread dough
Split between the 12 holes and press down - spoons, a pastry pusher or even a coffee tamper can make this easier. Flouring the object can also help to push it down.
Bake for 15-18 minutes until golden and cool in the tin whilst you make the caramel
Add the butter, sugar, syrup and condensed milk to a pan
Heat on a low heat to melt the butter and dissolve sugar
Turn up the heat to medium-high and boil for 4-6 minutes until golden and thickened
Carefully split between the 12 and set in the fridge - I find it easier to beat the caramel ever so slightly off the heat to stop it bubbling and then carefully spoon
Decorate with the two chocolates however you fancy and set again