Heat oven to 350. Line baking sheets with parchment paper or coat with non-stick cooking spray. Beat shortening, brown sugar, egg, milk and vanilla in large bowl at medium speed of electric mixer until well blended. Combine (whisk) flour, baking soda, salt and cinnamon in small bowl. Beat into shortening mixture at low speed until smooth. Stir in oats just a bit then stir in chocolate chips. Drop by rounded tablespoonfuls 2 inches apart onto prepared baking sheets.
Bake 9 to 11 minutes or until no longer shiny on top. Cool 2 minutes on baking sheet. Remove to wire rack to cool. (Mine bakes 9-10 min every time)
Notes
Bake just until the shine leaves. This will ensure a chewy cookie.