Preheat oven to 350 degrees F (177 degrees C).
Grease 2 donut pans and set aside.
Add graham crackers to a food processor. Pulse until a very fine consistency. Set aside.
In a large bowl, whisk together the melted butter, milk, granulated sugar, vanilla extract, salt, and the egg.
Add the graham crackers from step 3, sweet rice flour and baking powder into the bowl. Use a spatula to combine until you get a wet dough.
Spoon the dough into a pastry bag or Ziploc bag. Pipe the dough into the donut pans. I used a donut pan with donut molds that are 3 inches in diameter.
Bake for 9-11 minutes until a toothpick comes out clean.
Let donuts cool in the donut pan for 10 minutes. Transfer to a cooling rack to cool completely.
Once the donuts are cool, make your ganache. Add chocolate chips to a bowl. Heat heavy cream until bubbles start to form around the edges. The cream should be hot, not boiling. Pour cream over the chocolate chips. Let the mixture sit for a few minutes to soften the chocolate. Then mix until a smooth ganache forms. If the chocolate has trouble melting, microwave it in 10 second increments until the chocolate fully melts.
Dip the donuts into the ganache. Top with marshmallows. Use a kitchen torch to roast the top of the marshmallows and serve.