Preheat the oven to 350°F.
Grease a baking pan with cooking spray. Make sure it is well coated.
In a large mixing bowl, mix together the dry cake batter ingredients except graham crackers.
2 cups pancake mix, 1 cup cake flour, 3 tablespoons sugar, 2 teaspoons baking powder
Stir in the eggs and wet ingredients into the dry ingredients and mix until combined.
3 eggs, 1 ½ C milk, 1 teaspoon vanilla, 4 tablespoons butter
Fold in the chocolate chips.
Add crushed graham crackers.
Spread the batter into the sheet pan in an even layer and drizzle with chocolate fudge.
Bake for 16-19 minutes.
Pull the cake out of the oven and set aside on a cooling rack temporarily.
Set the oven to the Broil Low setting.
Once the oven reaches the correct temperature, dot the top of the cake with the mini marshmallows.
Put in the oven and broil for 6-7 minutes, watching carefully to make sure the marshmallows brown but do not burn.
Immediately garnish the entire cake with chocolate chips so they will melt on top.
Serve warm, and store any leftovers in an airtight container once they have cooled to room temperature.