Here is one s'mores recipe we wouldn't recommend putting over an open flame.
500 milliliters milk (any type will do)
2 scoops of vanilla ice cream (you may add more for a thicker shake)
1 teaspoon vanilla extract
2 tablespoons smooth peanut butter
1 cup roughly chopped graham cookies
Large and mini marshmallows
1 tablespoon cocoa powder
Dip the lip of each jar into chocolate sauce and let any excess drip off. Dip into crushed graham cookies. Squeeze chocolate sauce around the inside of your serving jar. Set aside.
Add milk, cocoa powder, ice cream and vanilla extract to a food blender and blend until everything is well combined. Pour into your serving jar.
Carefully place marshmallows on top and toast using a kitchen torch.