Preheat oven 150C/300F/Gas Mark 2

Lightly butter or line two baking trays.

Cream butter and the sugar in a large mixing bowl before gradually adding the flour and mixing until a dough forms.

Add the Toblerone pieces to the dough and knead until they are spread throughout the cookie dough.

Roll the shortbread dough out onto a lightly floured surface until it is about a cm thick. Cut into rounds using a cookie cutter and place evenly spaced on the baking sheets with a little bit of spreading room.

Bake for 15-20 minutes in the preheated oven until the cookies are just starting to brown on top.

Leave to cool slightly before transferring to a wire rack to cool completely.