Prep: Preheat your oven to 350°F (175°C) and line a cookie sheet with parchment paper.

Prepare the Dough: Melt the butter in the microwave. Transfer the melted butter to a large mixing bowl and add in the light brown sugar. Whisk the butter and sugar together until they form a smooth, creamy mixture.

Mix in Wet Ingredients: Add in the egg, vanilla extract and coffee. Beat the ingredients together until fully combined.

Add in Dry Ingredients: In a separate bowl, sift together the all-purpose flour, cocoa powder, baking soda, and kosher salt. Gradually fold these dry ingredients into the wet mixture until no dry flour bits remain.

Add Chocolate: Chop the dark chocolate and white chocolate into small chunks and mix well into the cookie dough.

Chill the Dough: Cover the bowl with wrap and place it in the fridge. While you can chill the dough for as little as an hour, for optimal flavor and texture, it’s best to let it rest overnight for the best flavour.

Bake: Remove the dough from the fridge and allow it to come to a scoopable temperature. Using an ice cream scoop, scoop a heaped scoop of dough and place them on the prepared baking sheet, leaving enough space between each cookie to allow for spreading.
Slide the baking sheet into the preheated oven and bake the cookies for 16-18 minutes, or until the edges are set but the centers remain slightly doughy. This ensures that perfect balance of chewiness and softness that makes these cookies irresistible.

Cool and Enjoy: Once baked to perfection, allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. Or, if you simply can’t resist, indulge in a warm, melty cookie straight from the oven!