This is a cake that begs for a tall pitcher of cold milk. Chocolate chips in the batter add textural contrast and a pure sense of fun, and an inspired combination of milk chocolate and caramel in a thick, rich frosting makes it an instant classic. Once the sugar syrup for the caramel comes to a boil, avoid stirring which can lead to crystallization of the sugar and make the caramel grainy. Use parchment paper to line the pans, and three 9-inch-diameter cardboard rounds (sold at bakery supply stores) to support the delicate cake layers. If you can?t find cardboard rounds, use tart pan bottoms instead. The cake will keep up to two days before serving.

12 SERVINGS

Cake

Nonstick vegetable oil spray
2 cups sifted cake flour (sifted, then measured)
1 cup unsweetened cocoa powder
1-¼ teaspoons baking soda
3/4 teaspoon salt
½ teaspoon baking powder
1-½ cups (packed) golden brown sugar
1 cup plus 2 tablespoons (2-¼ sticks) unsalted butter, room temperature
3 large eggs
1 tablespoon vanilla extract
1 cup plus 2 tablespoons buttermilk
½ cup lukewarm water
1 cup semisweet chocolate chips (about 6 ounces)

Frosting

24 ounces imported milk chocolate (such as Lindt), finely chopped
3 ounces bittersweet (not unsweetened) or semisweet chocolate, finely chopped
1-½ cups sugar
½ cup water
2-¼ cups whipping cream

FOR CAKE: Preheat oven to 350°F. Spray three 9-inch-diameter cake pans with 1-½-inch-high sides with nonstick spray. Line bottom of pans with parchment paper. Whisk flour and next 4 ingredients in medium bowl to blend. Using electric mixer, beat brown sugar and butter in large bowl until fluffy, about 2 minutes. Add eggs 1 at a time, beating well after each addition. Beat in vanilla. Beat in flour mixture in 3 additions alternately with buttermilk in 2 additions. Beat in ½ cup lukewarm water. Stir in chocolate chips.

DIVIDE batter among prepared pans (about 2-1/3 cups for each). Smooth tops. Bake cakes until tester inserted into center comes out clean, about 22 minutes. Cool completely in pans on racks. Invert cakes onto 9-inch-diameter cardboard rounds or tart pan bottoms (cakes will be delicate). Peel off parchment.

FOR FROSTING: Combine milk chocolate and bittersweet chocolate in large bowl. Stir sugar and ½ cup water in heavy medium saucepan over medium heat until sugar dissolves. Increase heat and boil without stirring until syrup is deep amber color, occasionally brushing down sides of pan with wet pastry brush and swirling pan, about 10 minutes. Carefully and slowly add whipping cream (mixture will bubble vigorously). Stir over low heat until any hard caramel bits dissolve and mixture is smooth. Pour caramel over chocolate; let stand 1 minute to allow chocolate to soften, then whisk until chocolate is melted and smooth. Refrigerate chocolate-caramel frosting until completely cool, about 2 hours. Let stand 1 hour at room temperature before continuing.

USING electric mixer, beat frosting just until color resembles milk chocolate and frosting is easily spreadable, about 1 minute (do not overbeat or frosting will become stiff and grainy). If necessary to correct graininess, set bowl with frosting over saucepan of simmering water for 10-second intervals, whisking just until frosting is smooth and spreadable.

PLACE 1 cake layer on platter, flat side up. Spread 1 cup frosting evenly over top. Top with second cake layer, flat side up, pressing slightly to adhere. Spread 1 cup frosting over top. Top with third cake layer, rounded side up, pressing slightly. Spread remaining frosting over sides and top of cake, swirling decoratively. (Can be prepared 2 days ahead. Cover with cake dome and store at room temperature.)