Preheat oven to 350 F. Line a 13x9 baking pan with foil, spray with non stick cooking spray.
Whisk together flour, espresso powder, baking soda, baking powder, and salt.
In mixer bowl, cream the butter and brown sugar. Add eggs one at a time, beating until incorporated. Add in the half & half and vanilla and mix well. Add the dry ingredients with mixer on low speed until incorporated. Stir in chocolate chips.
Bake in preheated oven for 22-28 (mine took 24 minutes). Cool on a wire rack in pan then lift bars out by the foil. Cut into bars.