In a large bowl, sift together the flour, baking powder, and salt. Set aside.
In a large bowl, cream together butter, shortening and sugar until smooth and no lumps remain.
Beat in eggs and vanilla.
Slowly stir in the flour, baking powder, and salt mixture.
Cover, and chill dough for at least one hour (or overnight).
Preheat oven to 400 degrees F (200 degrees C). Roll out dough on floured surface ¼ to ½ inch thick. Add a little more flour as needed for sticky dough.
Cut into shapes using Mickey Mouse (or any) cookie cutter.
Place cookies 1 inch apart on ungreased cookie sheets.
Bake 6 to 8 minutes (depending on size and thickness) in preheated oven. Cool two minutes on baking sheet so they can set and then transfer to wire racks to cool completely.
Frost and decorate once completely cooled.
Recipe by Wishes and Dishes at https://wishesndishes.com/minnie-mouse-sugar-cookies/