Mix the wet ingredients

• Melt the butter in a bowl.
• Stir in the brown sugar and granulated sugar until smooth.
• Add the egg yolk and vanilla extract and mix well.

Add the dry ingredients

• Add the flour, baking soda and salt.
• Fold in the chocolate chips until just combined.

Shape the cookies

• Divide the dough into two balls.
• Place them on a lined baking tray and flatten slightly.

Bake

• Bake at 180 °C until the edges are set and the centers are soft.

Cool

• Let the cookies cool on the tray for a few minutes before eating.