S’Mores Brownies 
 
1 cup (8 oz/250 g) unsalted butter, plus more for greasing  
10 oz (315 g) bittersweet chocolate, finely chopped  
1 cup (8 oz/250 g) granulated sugar  
¾ cup (6 oz/185 g) firmly packed light brown sugar  
4 large eggs  
2 teaspoons pure vanilla extract  
1 teaspoon kosher salt  
1 1 ⁄3 cups (5½ oz/170 g) cake flour  
3 tablespoons natural cocoa powder  
About 6 graham crackers, roughly crushed with your hands  
About 12 jumbo marshmallows  

Makes 12 brownies 

Preheat the oven to 350°F (180°C). Generously butter a 9-by-13-inch (23-by-33-cm) baking dish. 

In a large saucepan over low heat, combine the butter and chocolate and heat, stirring often, until melted, about 4 minutes. Remove from the heat and whisk in the granulated sugar and brown sugar. Whisk in the eggs one at a time, beating well after each addition. Whisk in the vanilla and salt. 

Sift the flour and cocoa powder over the chocolate mixture and, using a rubber spatula, stir in until just blended. Stir in the graham crackers. 

Pour the batter into the prepared baking dish and spread evenly. Top evenly with the marshmallows. 

Tip: To make it easier to cut the brownies, fill a tall glass or pitcher with very hot water. Dip your knife in the water and wipe it off with a paper towel before each cut. This technique also works great for cutting cookie bars and frosted layer cakes.