Rocky Road Brownies

Preheat oven to 350ºF. Grease a 9 x 13 inch baking pan.

In a large heatproof bowl, combine butter and 2 cups chocolate chips. Melt in the microwave on high power for 2 to 3 minutes, stirring every 30 seconds.

Into the chocolate/butter mixture, stir in sugars and salt. Once combined, stir in the eggs and then the flour, stirring just until combined. Mix in 1/2 cup of the walnuts. Spread batter evenly in the prepared pan. Bake for 20 or 25 minutes, until an inserted toothpick comes out with crumbs.

Remove from the oven. Sprinkle with remaining chopped nuts, chocolate chips and marshmallows. Bake until the marshmallows are puffed and beginning to brown and the chocolate turns shiny, roughly 5 to 7 minutes. (If you like your marshmallows extra toasty, turn on the boiler of your oven and use that for the last few minutes. Be sure to turn the pan every minute or so to ensure even browning.)

Remove from the oven and cool completely in the pan.