How to Make It
In a bowl whisk the flour, milk powder and sugar. Using your fingers, work in the canola oil until incorporated. Stir in the water to form a thick batter, then stir in the chocolate chips.
Preheat a flameproof rimmed griddle and brush lightly with olive oil. Scoop the batter into eight 1/4-cup mounds and spread each one to 3 inches. Cook over very low head until lightly browned on the bottom, about 2 minutes. Brush the tops lightly with olive oil and flip. Spread the jam over the biscuits, cover the griddle and cook until the biscuits are puffed and golden, about 2 minutes longer.
Meanwhile, thread the marshmallows on the rosemary branches and toast until golden and melted. Sandwich the marshmallows between the biscuits, jam sides in, and pull to remove the skewers. Serve the s'mores right away.