Beat together the butter and sugar with a hand held mixer or a stand up mixer. Then add in the eggs, milk and vanilla extract. Mix until combined.
In a separate bowl, whisk together the dry ingredients: flour, baking powder and salt.
Then gradually stir the dry ingredients (flour mixture) into the wet ingredients (butter mixture) until a dough forms. Cover and chill the dough for at least 2 hours.
Then preheat the oven to 350 degrees F.
Use a teaspoon or cookie scoop to drop the cookie dough onto a prepared baking sheet into round balls. Flatten the cookie dough out slightly by using the bottom of a glass dipped in granulated sugar.
Then bake for 12-15 minutes until the cookies are slightly golden brown. Make sure to rotate the baking sheets halfway through the baking time to ensure that the cookies are baked evenly.
Let the cookies sit on the baking sheet for 5 minutes. Then move the cookies to wire racks to cool completely.