Preheat oven to 350 degrees and line 2 baking sheets with parchment paper. Set aside.

In a bowl, melt chocolate chips and butter in 20-second increments in the microwave stirring in between until melted. Set aside.

In a stand mixer fitted with a whisk attachment whisk eggs and sugar starting out slow and increasing speed to high. Whisk until pale yellow. About 3 minutes.

While eggs and sugar are beating, in a plastic quart container or small bowl add cocoa powder, flour, salt, baking powder, and espresso powder. Stir to combine.

Once eggs and sugar are pale yellow, add the melted butter/chocolate mixture. Whisk on medium-low until combined.

Remove the bowl from the mixer and add dry ingredients and ⅔ of the chopped Heath bar. Mix by hand with a spatula scraping the sides of the bowl until the ingredients are combined.

Using a cookie scoop, scoop the dough onto prepared baking sheets and bake for 10 minutes. Bake cookies once the dough is mixed to ensure a fudgy chewy texture.

Allow the cookies to cool on the hot pan for at least 5 minutes before moving to a cooling rack.