Place a graham cracker and piece of chocolate on a plate and microwave for 10-15 seconds.
Grab one jumbo and one regular marshmallow, place them sideways (with the circles on the sides), then cut off a small amount of the bottom. This allows the marshmallows to stick to what's under it so they don't fall over.
Draw Baymax's eyes on your large marshmallow.
Place the marshmallows on the chocolate and graham cracker base.
Use a propane food torch (in a well-ventilated area) to toast your marshmallows. Do a practice round or two, this is a bit tricky at first :)