Ingredients

Makes 1 dozen

　　1 3/4 sticks (14 tablespoons) unsalted butter

　　46 ounces semisweet chocolate, cut into 1-inch pieces

　　3 large eggs, lightly beaten

　　1/2 teaspoon salt

　　1 cup granulated sugar

　　1/2 cup packed light-brown sugar

　　1 teaspoon pure vanilla extract

　　3/4 cup all-purpose flour

　　2 quarts vanilla ice cream

　　

Step 1

Preheat the oven to 350°F. Line a 9 × 13-inch baking dish with parchment paper; set aside. Melt 1 1/2 sticks butter and 6 ounces chocolate in a heatproof bowl set over a pan of simmering water, stirring; set aside.

　　

Step 2

Whisk together the eggs, salt, sugars, and vanilla in a large bowl. Stir in the chocolate mixture; fold in the flour. Pour the batter into the lined baking dish. Bake until the top is shiny, about 20 minutes. Let cool in the dish on a wire rack. Cover; let stand 8 hours (or overnight).

　　

Step 3

Run a thin knife around the edges of the brownie; invert to unmold onto a cutting board. Remove the parchment. Trim 1/4 inch from the edges of the brownie. Line the baking dish with a clean sheet of parchment paper, leaving a 3-inch overhang on the long sides. Return the brownie to the dish, top side up; set aside.

　　

Step 4

Mix half the ice cream in the bowl of an electric mixer fitted with the paddle attachment until smooth but not melted; spread over the brownie. Cover; freeze 1 hour.

　　

Step 5

Mix the remaining ice cream, and spread over the frozen layer of ice cream on the brownie. Cover; freeze 1 hour (or overnight).

　　

Step 6

Melt the remaining 40 ounces chocolate with the remaining 2 tablespoons butter. Let cool.

　　

Step 7

Transfer the brownie to a cutting board. Dip a knife in hot water; wipe dry. Trim 1/4 inch from the edges. Cut the brownie into 12 bars, dipping the knife as needed. Transfer to a wire rack set over a baking sheet. Ladle the chocolate mixture over the bars. Freeze 30 minutes.

　　Reprinted with permission from The Martha Stewart Living Cookbook: The New Classics by Martha Stewart Living Magazine, copyright © 2007. Published by Clarkson Potter, a division of The Crown Publishing Group.Buy the full book from Amazon.