01 -
Get your oven going at 350°F (175°C).
02 -
Use a food processor to grind graham crackers into crumbs until fine.
03 -
Combine the crumbs with sugar and melted butter in a bowl. Stir until blended.
04 -
In a 9x13-inch dish lined with parchment, press the graham mixture down completely.
05 -
Mix the brownie batter as explained on the package.
06 -
Spread the brownie batter evenly across the prepared crust.
07 -
Pop the dish into the oven and bake for 22-25 minutes. The center should feel firm.
08 -
Scatter the chocolate chips and marshmallows over the cooked brownies right away.
09 -
Switch to broil and toast the marshmallows in the oven for about 3 minutes until golden. Watch them closely so they don’t burn.
10 -
Let everything chill out before slicing and digging in.