Place the butter, brown sugar, and granulated sugar in the work bowl of an electric mixer fitted with a paddle attachment. Beat on medium speed for about 30 seconds, until the mixture is fluffy.
Beat in the egg and vanilla for 30 seconds longer until well combined.
In a mixing bowl, sift together the flour, baking powder, baking soda, and salt.
Add to the mixer, while beating on low speed. Beat for about 15 seconds, stir in the chocolate chips and espresso powder, and mix for 15 seconds longer.
Place parchment paper on a cookie sheet.
Using a 1-ounce scoop, drop the cookie dough onto the cookie sheet in dollops about 3" apart.
Gently press down on the dough with the back of a spoon to spread out into 2" circles.
Transfer to the oven and bake for about 20 minutes or until the cookies are nicely browned around the edges.