Ensure the butter and egg are at room temperature; the butter should be soft but not melted.

Whisk one egg in a bowl, then measure out 25 grams to use in the recipe.

Combine instant coffee with water and set aside.

To make the cookie dough:

No mixer is needed. Use a rubber spatula to blend the softened butter and brown sugar. Incorporate the room-temperature egg and mix well. Add the vanilla extract and the instant coffee mixture, mixing until combined.

Sift the dry ingredients into the butter mixture, then add the oil. Begin mixing with a spatula. The dough will be crumbly at first. Continue mixing until a rough dough forms, with some flour visible. Fold in the chocolate chips and mix until a sticky dough forms.

Chill the dough:

Cover and refrigerate the dough for at least 1 hour, or overnight for best results. The dough can be stored in the fridge for up to 3-4 days.

When ready to bake:

Preheat your oven to 350°F. If using a convection oven, reduce the temperature by 20°F.

Bake one tray at a time to ensure even results. Line a baking sheet with parchment paper.

Scoop about 8 grams of dough, roll into balls, and place them 1 inch apart on the baking sheet. If the dough is too soft, chill the tray in the freezer for 15 minutes to prevent excessive spreading.

For best results, bake 2-3 test cookies to determine spreading behavior. Adjust dough chilling time based on results. Bake for 18 minutes on a light-colored pan or 15-16 minutes on a dark-colored pan. Adjust time based on cookie size and oven performance. For crunchier cookies, bake an additional minute or two.

Cooling:

Cookies will be soft when first removed from the oven. Let them cool on the rack for 5 minutes before transferring to a cooling rack. They will crisp up as they cool.

If cookies lose crispiness, reheat at 350°F for 3-5 minutes. Allow to cool for crispiness to return.

For better flavor, wait until the next day to eat. Store cookies in an airtight container at room temperature for up to several weeks.