01 -
Fire up your oven to 350°F. Line a 9” baking pan with a sheet of parchment and lightly spray it with nonstick baking spray.
02 -
Follow the package directions to prepare the brownie batter. Pour it into the greased pan, making it as even as possible. Add spoonfuls of marshmallow cream over the top and swirl it gently in with a knife. No need for perfection—it'll bake just fine.
03 -
Bake as long as the mix directions mention. After baking, cool them all the way down. For a gooey texture, place them in the fridge for 1-2 hours.
04 -
In a big bowl, mix softened butter with an electric beater on medium. Do this for about two minutes until it’s creamy and airy.
05 -
Add the marshmallow fluff and keep beating until it’s all mixed together nicely.
06 -
Combine the powdered sugar gradually, one cup at a time. Start mixing at low speed, then increase to a faster setting. Check the bowl sides and scrape them clean. Blend in the vanilla and the green food coloring until the color is smooth with no streaks.
07 -
If your frosting feels too dense, a splash or two of heavy cream or milk can help thin it out. Beat it on high for another minute—this’ll make it light and fluffy.
08 -
Spread the frosting evenly over the brownies once they’ve cooled. Keep some aside if you don’t want to use it all. Sprinkle on marshmallows and edible gold flakes as the final touch.
09 -
Slice them into squares and dig in!