preheat oven to 350F
cream together 1/2 cup softened butter + 1 cup brown sugar + 2 tsp vanilla + 2 tbsp cooled espresso
whisk in 1 egg + 1 egg yolk
add in 1 1/2 cup flour + 1 tsp baking powder + 1/2 tsp baking soda
fold in 1 cup chocolate chips
add dough to a lined 9×9 pan and press down to evenly spread out throughout pan
bake for 25-30 min or until golden and toothpick comes out clean