In a large bowl cream together your butter and sugar.

In a small cup combine the hot chocolate mix with the hot water.

Add chocolate mixture and egg yolk to the butter mixture. Mix until well combined.

Add in the flour and fold together until it forms a soft dough.

Sprinkle icing sugar over your work surface and rolling pin. Roll out your dough until it is about 1.5 cm thick.

Using a 9cm round cutter (or drinking glass) cut out as many cookies as you can. Transfer the cut dough onto a lined baking sheet. Leave a few centimeters of space between each cookie. Re-form the dough into a ball. Roll out the dough and cut rounds as you did before. Repeat this until all of the dough has been used.

To turn your rounds into buttons, find a small round lid ( I like to use a milk bottle lid). Use the flat side of the lid to indent the centre of your cookie. Next take a toothpick, make a small indent where you want the holes to be and gently press down in a small swirling motion until you have the button hole desired. Repeat to make 2-4 small holes in your button.

Add indents and holes to all of your cookie buttons.

Chill your prepared cookie sheets in the fridge for 30 minutes.

Preheat oven to 160 degrees (180 fan)

Bake the chilled chilled cookies in batched for 12 minutes.

Let the cookies chill fully before placing into an airtight container to store.