1 cup, less 1 tablespoon, all-purpose flour
1/4 teaspoon baking powder
1/4 teaspoon salt
4 1/2 tablespoons unsalted butter
1/2 cup, plus 1 tablespoon, unsweetened cocoa powder*
pinch espresso powder
1 1/4 cups sugar
1 large egg
2 large egg whites
1 tablespoon vanilla extract
8 large marshmallows
2/3 cup pecans, roughly chopped
1/2 cup semi-sweet chocolate chips or chunks
Spray the bottom and sides 8 inch square baking dish with cooking spray; line with criss-crossing sheets of parchment paper (spray the bottom of the first sheet before adding the second; spray the second sheet as well); leave an overhang so you can easily remove the brownies later on.
Whisk flour, baking powder, and salt in a small bowl. Set aside.
Melt butter in medium saucepan until it sizzles; remove from heat. Add cocoa powder and espresso powder, mix until combined. Add the sugar and stir until well-mixed - it will resemble very dark brown sugar in texture. Add eggs and vanilla, stir until glossy and smooth. Add flour and stir to combine, then beat 50 strokes by hand (the batter is very thick - you will get a bit of a workout here).
Transfer the batter to the square pan. Cover and refrigerate 2 hours.
Heat a large skillet over medium. Toast pecans until they start to brown slightly and smell "nutty." Set aside.
Remove pan from refrigerator for 30 minutes to warm slightly.
Preheat oven to 350*F.
With an oiled knife (use a neutral oil, such as canola or vegetable), quarter the marshmallows and spread over the brownie batter. Push slightly into the batter. Sprinkle nuts and chocolate chips over batter. Bake 25-30 minutes, until the marshmallows are lightly browned.
Cool completely in pan on wire rack, about 2 hours. Lift parchment edges to remove brownies from pan; cut into 16 squares.
*Medrich recommends using natural cocoa powder, but I decided to try this recipe using Dutched cocoa. Generally, natural and Dutched cocoa powders are not interchangeable, but since brownies often don't include leavening in the recipe (and this recipe does include a little baking powder), I decided to go ahead and try it anyway. Usually, if you're using Dutched cocoa powder in a recipe calling for natural cocoa, the recipe will need some additional leavening, generally baking soda.