In a large bowl, cream together the
shortening and sugar until light and fluffy. Add the eggs one at a
time, beating well with each addition, then stir in the vanilla
and sour milk. Combine the flour, baking powder, baking soda, salt
and cinnamon, gradually stir into the creamed mixture. Finally,
stir in the rolled oats, and your choice of additions. Drop by
rounded spoonfuls onto the prepared cookie sheets.