1. Whisk flour with sugar, baking powder and salt in a small bowl.
2. Whisk milk with oil, eggs and vanilla in large bowl.
3. Whisk in flour mixture until combined.
4. Stir in 10 chopped caramel butter cookies.
5. Scrape mixture into a well-oiled 10-inch cast iron skillet, smoothing top.
6. Set pan over a grill on medium, lid closed, or on a campfire grill, covered, until a tester inserted into centre of cake comes out clean, 30 to 40 minutes.
7. Immediately sprinkle with marshmallows.
8. Let stand to cool slightly, then top with remaining 6 chopped cookies and strawberries.

Tip

Shortcake can be baked in centre of a 350F oven, 40 min. Camping? For easy travelling and cleanup, whisk then store dry ingredients and prepared shortcake toppings in reseal able bags.