Preheat oven to 350 degrees
Line two full sheet cookie sheet pans with parchment paper
Using a mixer, cream together the butter, powder sugar, vanilla and egg, and mix until combined and creamy
Using a large bowl, combine the flour, baking soda and cream of tartar
Gradually add in the dry ingredients and mix on low speed
Using your hands continue to mix until fully combined
Lightly flour a cutting board and knead the cookie dough a couple of times
Roll out the dough to about ½ inch thick
Cut out 48 rounds and place a minimum of 12-15 cookies onto a cookie sheet. Bake for 8 minutes or until lightly golden brownRepeat steps until completely out of dough Let cookies cool completely
Putting the cookies together directions:Pair up the cookies based on matching the size and create 24 sandwich cookie shells Using a large spoon, scoop some of the butter and place onto the bottom cookiePlace the top cookie onto the bottom cookie and sandwich together Enjoy!