Preheat oven to 375 degrees.
Start by creaming the butter and sugar together.
Beat in the egg, vanilla, and baking powder.
Mixing between each addition, sift in the flour, one cup at a time.
Now, divide the dough into two halves, and roll out one half at a time on a layer of waxed paper. (I like mine rolled out about 3/8 of an inch thick, but you can do whatever thickness you want!)
Grab your cookie cutters and dip them in flour. Cut out your shapes and place on an ungreased cookie sheet.
Bake for 5 minutes, pull out, turn around, and bake for another 2 minutes. Cool on a wire rack.
While cookies are cooling, make the frosting by combining the melted butter and vanilla.
Add the powdered sugar and milk.
If you want, divide frosting into different bowls and add some food coloring!
Frost your cookies, let them set for about 15 minutes for the frosting to set up and store in an air-tight container.
Enjoy!