These old fashioned oatmeal cookies are so stinking good... add the icing to take them over the top!
Preheat oven to 350°F. Use non-stick baking sheets or line sheets with parchment or silicone mats.
Whisk together the flour, baking soda, baking powder, cinnamon, and salt. Set aside.
Cream together the shortening, butter, and sugar.
Add in the egg and vanilla, mix well.
Next add in the dry ingredients and mix.
Lastly, add in the oats and mix until well combined.
Drop by rounded tablespoons onto the cookie sheets. Bake at 350°F for 10-12 minutes.
Remove from oven and allow the cookies to set on baking sheets for a couple of minutes before removing to wire racks to cool.
Combine the powdered sugar and vanilla. Add milk 1 tablespoon at a time, mixing well after each addition. Add milk until a thin, spreadable consistency is reached.
Spoon 1 tablespoon of icing onto cooled cookies. Add sprinkles while icing is still wet, if desired.