Preheat oven to 350°F (175°C).

In a large bowl, cream together the shortening, white sugar, and brown sugar.

Beat in the eggs one at a time, then stir in the vanilla.

In a separate bowl, whisk together the flour, baking soda, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Stir in the oatmeal and chocolate chips (if using).

Drop by rounded tablespoons onto ungreased cookie sheets.

Bake for 10 minutes, or until edges are lightly golden brown.

Let cool on the baking sheets for a few minutes before transferring to a wire rack to cool completely.