Follow directions on cake mix box to bake cupcakes, chocolate works best so it looks like dirt on the bottom.
Allow to completely cool before frosting or decorating them. In the meantime color frosting red and brown. Spoon both into separate pint size freezer bags or pastry bags with a tip on it.
Use the brown frosting to make large dots on the top all the way around in two rows leaving the middle open. Use the red frosting to make dollops of "fire flames" in the center that are somewhat high.
Break pretzels in half, or leave as is, leaning them against one another to create a log look with a peak at the top.
Add mini marshmallows to other pretzel sticks at the ends to look like they are ready for roasting.