Preheat oven to 350°F. Place the walnuts on a cookie sheet. Bake for 10-15 minutes or until golden and fragrant. Let cool slightly and then roughly chop.
Bring a small sauce pot filled with 1 inch of water to a low simmer. Place a heat proof bowl over the pot.
Place the chopped chocolate in the bowl and stir until fully melted, making sure the chocolate doesn’t burn.
Remove the chocolate from the heat and let cool for about 5 minutes. Stir in the chopped walnuts and marshmallows. Pour onto a sheet tray lined with parchment paper and smooth into an even layer. Sprinkle evenly with the crushed graham crackers and salt.
Let cool fully or place in the freezer for 20 minutes, then break into large pieces.
Recipe Courtesy of Megan Mitchell