In the bowl of a stand mixer fitted with a paddle attachment, beat the shortening, sugar, egg, vanilla and molasses until fluffy. Alternatively, use a handheld electric mixer and a large bowl.
In a medium bowl, combine the oats, flour, cinnamon, baking powder and salt.
With the mixer on low speed, add the dry ingredients into the wet ingredients.
Cover the bowl and refrigerate for at least 1 hour.
Preheat oven to 350 degrees. Line two baking sheets with parchment paper. Drop rounded spoonfuls of cookie batter onto a parchment-lined cookie sheet, spaced at least 1" apart. Bake cookies for 14-16 minutes.
Allow the cookies to cool on the baking sheet for 5 minutes before removing to a wire rack.