Mix dry ingredients (flour, oats, baking soda, salt & cinnamon). Set aside.
In a separate bowl, cream together shortening, butter, and both sugars until fluffy. Add eggs, one at a time, beating after each addition. Add vanilla and lemon juice and beat well.
Slowly add in dry ingredients, beating on low until combined. Stir in chocolate chips. Cover tightly with plastic wrap and refrigerate overnight.
Preheat oven to 350. Line baking sheets with parchment paper.
Using a small cookie scoop, place 1 scoop on the bottom of the oreo, and one scoop on the top.
Flatten dough around cookie, covering completely, but without a lot of excess dough. (Too much extra dough will cause the cookie to spread quite a bit around the oreo once cooked, and won't look as "pretty")
Place on baking sheet and bake for 11-13 minutes, or until cookies begin to turn golden on the top and around the edges.
Cool on pan for 5 minutes before transfering to a wire rack to cool completely.