Line a baking sheet with parchment paper and set it aside for now.
In a bowl, combine the flours, cocoa, instant espresso powder, baking soda, and salt. Whisk them together and set this aside for a moment.
In your mixing bowl, beat the butter and coconut sugar together until they are fluffy.
Add in the egg and egg yolk. Beat until smooth and creamy.
Add in the dry ingredients and mix until combined. Scrape the bowl with a rubber spatula to make sure all of the ingredients are combined.
Stir in the chocolate chips.
Scoop the cookie dough by rounded teaspoons onto your prepared baking sheet. I use a scoop so that the cookies are all the same size, but you can use a spoon if you prefer.
Bake the cookies for 8-9 minutes.
Cool the cookies on the baking sheet for a few minutes before transferring to a cooling rack to cool completely.