I like to use a stand mixer to make these cookies. You can certainly make this cookie dough by hand, but it will take a little longer (and a little arm muscle)!
For best results, let the butter soften to room temperature before using. Softened butter combines more easily resulting in a uniform texture. I like to take it out of the refrigerator about an hour before making the cookie dough.
You can use milk chocolate, white chocolate, non-dairy any chocolate will work. Overall taste profile might change a bit.
I am using dark brown sugar in my recipe. If you use light brown sugar, color and texture might be a bit different.
Use liquid espresso for this cookie recipe. Espresso powder will make the cookies too dry.