Method : 

• Heat the oven to 180 c
• Line two baking trays with parchment.
• Cream the butter and sugars together in a mixing bowl until light and fluffy. You can use an electric whisk if you like.
• Add the chocolate chips & any other chocolate or ingredient you want at this stage.
• Beat the eggs in a bowl with a fork then add them to the mixture.
• Add the Vanilla extract.
• Mix the bicarbonate of soda and the salt into the flour
• Add the flour to the mixture, then slowly combine it with a fork until it forms a tight cookie dough.
• Put the dough in the fridge for 30 minuets. 

• To make Large Cookies you are going to want an 80 g ball of dough.
• For a smaller cookie try a 50 g ball.
• Put the dough balls about 4 - 6 inches apart on a baking tray, lined with silicon paper
• Put the cookies in a preheated oven @180 c for 10 - 11 minutes (No longer than 11)
• Take them out and allow them to cool before transferring them to a wire rack for further cooling.
• Remember the cookies will be soft when you take them out of the oven, so let them cool.