To Make the Sugar Cookies:

1. Add half of the flour to a mixing bowl. Add the baking powder and salt to the flour in the bowl and use a whisk to combine. Set the other half of the flour aside. 
2. In a separate bowl, cream the butter and sugar until light and fluffy (use an electric mixer or stand mixer.) Add eggs, milk, and vanilla to the creamed butter and sugar. Beat on medium-low speed until combined. 
3. Mix in the portion of the flour that contains baking powder and salt to the butter mixture. Then gradually mix in the remaining flour that you had set aside. Only add enough flour until everything forms a smooth dough. You may not need to add the whole amount. Adding too much flour will toughen the cookies. The dough shouldn’t be loose and gooey, but not too stiff either. It’s ok if the dough is a little bit soft because it will firm up as it chills. 
4. Split the dough in half and place each half into a plastic bag, or wrap it in plastic wrap. Place into the fridge to chill for 1-2 hours. 
5. After the dough has chilled, heat the oven to 400 degrees Fahrenheit. 
6. On a floured surface, roll out the dough to about ¼-inch thick. Use cookie cutters dipped in flour to cut out the cookies. Place the cookies onto an ungreased cookie sheet, about 1 inch apart.  (I like to line mine with a silicone mat or parchment paper, but this is optional.) Bake for 8-9 minutes, or until the edges become just barely lightly golden. Don’t overbake or your cookies will be tough. 
7. Repeat rolling, cutting, and baking until you use up all of the dough. You can reroll the scraps to make more cookies. If the dough gets too soft at any time during the process, form it into a ball or disc and pop it into the refrigerator to firm up again. 
8. Allow cookies to cool for 5 minutes on the pan before transferring them to a wire rack to cool completely before icing.

To Ice the Sugar Cookies:

1. Use a whisk or spoon to mix the icing ingredients together. Adjust the icing to your desired consistency by adding powdered sugar to make it thicker, or adding milk to thin it out. Divide into bowls and color the icing with food coloring.
2. Ice the cookies using a butter knife, or another utensil for frosting. Or you can use icing bottles or a piping bag.
3. For the best results, allow the iced cookies to sit undisturbed overnight to allow time to dry. Don’t stack the cookies until the icing is firm and completely dry.