Preheat oven to 375. Melt butter and set aside to cool.
Mix all ingredients except for the powdered sugar and chocolate chips in a bowl on medium speed until well blended, then add the chocolate chips. Mix the chocolate chips by hand until thoroughly mixed into the batter.
Roll dough by heaping tablespoons into little balls, then drop in the powdered sugar. Roll around until completely and evenly coated, then place on an ungreased cookie sheet about 2 inches apart.
Bake for 9 to 11 minutes, then set aside to cool. I normally cook mine for 10 minutes, as I like a little softer cookie!