Make the cookie dough. In a large mixing bowl, add cold butter and coconut sugar. Mix on high until no clumps of butter remain, about 2 to 3 minutes.

Then, add in egg and vanilla. Stir to combine.

Add in flour, baking soda and sea salt. Stir to combine.

Then, make the brownie batter.

Add melted butter and 1 cup dark chocolate chips to a bowl. Stir until creamy and fully melted. If needed, microwave for 10 to 15 seconds. Set aside.

In a mixing bowl, add eggs and sugar. Whisk vigorously for 2 to 3 minutes, until light and frothy.

Add the melted chocolate mixture to the mixing bowl. Stir to combine.

Then, add in dark cocoa powder, vanilla, flour and espresso powder. Stir to combine.

Fold in extra chocolate chips if desired.

Pour batter into the pie plate on top of the cookie dough. Smooth out into one even layer.

Bake for 36 to 40 minutes, or until the edges are set and the middle is no longer jiggly.

Finally, remove from the oven. Cool for at least 4 hours before slicing and serving.