1. Mix flour, granulated sugar, salt and baking powder in a large bowl.
2. In a separate bowl, mix melted butter, brown sugar, eggs and vanilla extract until blended.
3. Pour butter mixture into flour mixture and mix together until well blended, adding milk halfway through mixing.
4. Refrigerate for about an hour or freeze for 20-30 minutes, until dough is firm. Meanwhile, preheat oven to 350 degrees.
5. Drop rounded tablespoons of dough onto baking sheets covered with aluminum foil or parchment paper.
6. Bake about 10 minutes, or until edges are brown and center of cookie is still soft.
7. Let sit on cookie sheet for 2 minutes them move to wire rack to finish cooling.