Cream together the sugar and butter, for about 2 minutes until light and totally mixed.
Add in the eggs, milk, and vanilla extract and stir in.
In a separate bowl combine the flour, baking powder and salt.
Slowly pour the dry ingredients into the wet ingredients while mixing.
With your hands, shape the dough into a ball. Cover the dough with plastic wrap or place in a ziplock bag. Place in the fridge for at least 2 hours, or overnight.
After the dough has been chilled, preheat the oven to 400 degrees.
Line a cookie sheet with parchment paper or a silicone liner.
Lightly flour your counter tops and roll out the dough. Roll the dough out to be about 3/8 to 1/2 inch thick. (Keep the extra dough in the fridge till needed)
Cut your dough into Christmas tree shapes and place cookie dough about 1 inch apart on the cookie sheet.
Re roll the remaining dough and cut into trees.
Place the cookie pan back in the oven for about 5 to 10 minutes to chill again.
Bake cookies for 6 to 7 minutes, or just until the top is set.
Allow the cookies to cool for about 5 minutes on the pan, and then remove to a cooling rack to cool completely.