First of all pre-heat the oven to 350ºF {180ºC}

In a mixing bowl, put the butter and the chocolate chips and take them to the microwave for 2-3 minutes {depending on your microwave potency}.

About half time stir and put it back.

It should be ready when it’s completely melted and smooth.

If you don’t have a microwave you can always go for “bain-marie or double bath” {hot water bath}.

Then stir the sugar, salt, and vanilla and mix well.

Let it cool for a few minutes so it doesn’t cook the eggs.

Then start adding the eggs. These should be added one at a time mixing well until they are completely incorporated.

Then add the flour and baking soda and stir strongly with preferably a wooden spoon. It gets very hard so you have to put a lot into it.

Mix until the batter is smooth and shiny – don’t overmix.

Lastly, add the mars bar chunks and mix.

In a baking tray, spray some butter and place about a spoon per cooky.

Make sure to leave space so when they grow, they don’t stick together.

Bake for about 10-12 minutes or until you see them slightly cracked and puffed up.

Take them out so they still are soft and gooey. The key here is to slightly underbake them.

Let the cookies cool for a few minutes on the hot cookie sheet, then transfer them to a cooling rack.