Mars Bar (Milky Way) Cookies

Preheat the oven to 190°C (Gas Mark 5 / 375°F).

In a large bowl, cream together the butter and sugar and then mix in 1 whole egg plus 1 egg yolk. Then mix in the vanilla essence.

Next add the flour and baking powder, and stir until well combined. The mixture should be fairly thick, but add a small dash of milk if required. Add the Mars Bar pieces and stir until they are evenly distributed through the cookie dough.

Line a baking tray with baking paper. Roll small amounts of the dough between your palms to form balls. I found slightly smaller balls worked better. Place the balls on the lined baking tray, leaving plenty of room between them for the cookies to expand (at least 3 inches, but exactly how much room you need will depend on how big your balls of dough are).

Bake for around 15 minutes, until the edges are just beginning to turn golden (but keep an eye on them to ensure they are not overcooked). Remove from the oven and leave on the baking tray for 5-10 minutes to firm up. Then transfer to a cooling rack to cool completely.