first question making smores cupcakes want the graham cracker to be the first layer I would just melt butter and crumbs and then bake in oven 7 minutes would that make my liners get messed up and then if I added in the batter and baked would it make the batter dry?

Second question anyone have a good recipe that travels well for marshmallow buttercream will be in a cool car for an hour then another hour sitting in the car S it's a baptism I have to go to and can't bring the cupcakes into the church. Will keep cupcakes in a hot cold bag with some ice packs on top 

Recipe I use 2 sticks of butter 3 cups p sugar 1 small jar of fluff and some vanilla but it don't hold up well to high temps 

anyone have anything better. Sorry if it looks jumbled my post but connected from my iPhone