Pre-heat oven to 375 degrees and line a cookie sheet with parchment paper or a silicone mat; set aside
In the bowl of an electric mixer with a paddle attachment, beat butter, shortening and sugars on medium-high speed until well combined (about one minute); add egg yolk and vanilla and mix on medium speed until combined
In a separate small bowl, whisk flour, baking soda, baking powder, salt and espresso powder; slowly add to mixer while on low speed and mix just until combined; stir in chocolate chips
Spoon cookie dough into prepared baking sheet (I used a medium cookie dough scoop) and bake 8-9 minutes or until edges are lightly browned; remove from baking sheet and place on a wire rack to cool (or better yet, eat warm out of the oven!)