Please make sure that the egg and butter are at room temperature. The butter should be soft but NOT melty.

Crack one whole egg in a bowl and whisk to loosen up the egg. Measure out 25 grams of egg to be used in the recipe. It is important to measure by weight.

Mix instant coffee with water and set aside.

Mash the softened butter with the brown sugar using a rubber spatula. Then add the room-temperature egg and mix again until combined. Add the instant coffee mixture and vanilla extract and mix again.

Sift the dry ingredients into the butter mixture. Add oil. Use a spatula to start mixing. The mixture will still be dry at first. Just keep mixing and when you get a rough dough, fold in the chocolate chips and continue to mix into a dough. It will be sticky.

Cover and refrigerate the cookie dough for at least 1 hour. If you can do it overnight, that's even better.

Preheat the oven to 350 F (180 C) for a conventional oven. For a convection oven, lower the temperature by 20 F or 15 C.

Line the baking pan with parchment paper.

Scoop about 8 grams of the cookie dough and roll into a round ball and put them about 1 inch apart as they will spread some during baking.

If the cookies have gotten too soft after all the handling, you can put the whole tray in the freezer again for 15 minutes before baking.

Bake for 18 minutes if you use a light color pan and about 15-16 minutes if you use a dark color pan.

Let the cookies cool down on the pan for 5 minutes and then remove and cool down completely at a cooling rack.

Store the cookies in an air-tight cookie jar. They can be kept this way at room temperature for weeks.