Start by gathering all your ingredients and tools on the counter.
Using a butter knife, take 3 tablespoons of peanut butter and spread it evenly on one slice of bread.
Next, scoop out 3 tablespoons of marshmallow fluff and spread it on the second slice of bread.
Carefully place the slice of bread with peanut butter on top of the slice with marshmallow fluff.
For a warm and gooey variation, you can toast the sandwich in a grill or pan over medium heat for 2-3 minutes on each side.
Once assembled, slice the sandwich diagonally or into quarters and serve immediately.
