Preheat oven to 350°
Cream the butter and sugar together for 2 minutes.
Scrape sides of bowl and add egg white and vanilla. Combine thoroughly.
Mix in flour and baking powder until completely combined. The texture should be similar to playdoh. If it is too wet, at a little more flour. If it is too dry, at a little water. 1 1/2 cups is always about perfect for me.
Roll out onto parchment paper. Use stencil and cut desired number, letter or shape twice.
Remove scraps from the parchment paper.
Carefully put the parchment paper (with the cookies on it) onto a cookie sheet. Bake at 350° for 10 -12 minutes. Pull when the center is puffy, no longer glossy and the edges are barely starting to turn color.
Cream together all butter cream ingredients.
Pipe large dots onto the cooled cookie. Top with the second cookie and repeat the piping process.
Decorate the top with a variety of candy.