Preheat oven to 350 degrees
In a medium bowl, combine flour, baking powder and salt; set aside
In a large mixing bowl, cream together the shortening, butter and sugars with an electric mixer
Lower speed and add eggs and vanilla, continuing to mix
Add dry mixture, combining until dough comes together
Roll into walnut-sized balls and roll in sugar {do not roll in sugar if frosting cookies}
Place on ungreased cookie sheet 2 inches apart
Bake for 10-12 min, or until bottoms are light brown
Cool on wire racks
Frost, if desired