Chocolate Crunch Layer Cake with Milk Chocolate Frosting

Preparation Position rack in center of oven and preheat to 350°F. Butter two 9-inch-diameter cake pans with 1 3/4-inch-high sides. Line bottoms of pans with waxed paper; butter paper. Dust pans with flour; tap out excess. Combine chocolate and 1/2 cup hot water in small saucepan. Stir over low heat until melted and smooth. Cool to lukewarm, stirring often. Whisk flour, baking soda and salt in medium bowl to blend. Using electric mixer, beat butter in large bowl until fluffy. Gradually beat in sugar. Beat in eggs 1 at a time, then vanilla extract. Beat in chocolate mixture. Add flour mixture in 3 additions alternately with milk in 2 additions, beating just to blend after each addition. Divide batter equally beween pans. Bake cakes until tester inserted into center comes out clean and cake just begins to pull away from sides of pan, about 35 minutes. Cool cakes in pans on racks 5 minutes. Cut around pan sides. Turn cakes out onto racks; peel off waxed paper. Cool cakes completely. Combine cream, corn syrup and butter in heavy large saucepan. Whisk over medium heat until mixture begins to simmer. Add chopped chocolate. Reduce heat to low and whisk until frosting is smooth, about 1 minute; transfer to large bowl. Fill another large bowl with ice. Set bottom of bowl with frosting atop ice. Whisk until frosting is cool and begins to thicken, about 8 minutes. Place bowl of frosting on work surface. Using electric mixer, beat until color lightens and just until frosting becomes thick enough to hold peaks when beaters are lifted, about 2 minutes (frosting will continue to thicken as it stands). Place 1 cake layer, flat side up, on 8-inch-diameter tart pan bottom or cardboard round. If desired, place pan bottom with cake atop 8-inch-diameter cake pan to make simple decorating stand. Top layer with 1 1/2 cups frosting, spreading to edge. Sprinkle evenly with diced toffee. Top with second cake layer, flat side down; press slightly to adhere. Spread thin layer of frosting over top and sides of cake to seal and set crumbs. Spread remaining frosting over top and sides of cake (if frosting becomes stiff, stir gently with spatula to loosen). Stand chocolate bar on 1 short end. Using vegetable peeler and starting at top edge of 1 side, run peeler down length of bar (chocolate will come away from side of chocolate bar in curls). Pile chocolate curls atop cake. Chill at least 2 hours. (Can be made 2 days ahead. Cover with cake dome and keep chilled. Let stand at room temperature 1 hour before serving.)

Preparation Position rack in center of oven and preheat to 350°F. Butter two 9-inch-diameter cake pans with 1 3/4-inch-high sides. Line bottoms of pans with waxed paper; butter paper. Dust pans with flour; tap out excess. Combine chocolate and 1/2 cup hot water in small saucepan. Stir over low heat until melted and smooth. Cool to lukewarm, stirring often. Whisk flour, baking soda and salt in medium bowl to blend. Using electric mixer, beat butter in large bowl until fluffy. Gradually beat in sugar. Beat in eggs 1 at a time, then vanilla extract. Beat in chocolate mixture. Add flour mixture in 3 additions alternately with milk in 2 additions, beating just to blend after each addition. Divide batter equally beween pans. Bake cakes until tester inserted into center comes out clean and cake just begins to pull away from sides of pan, about 35 minutes. Cool cakes in pans on racks 5 minutes. Cut around pan sides. Turn cakes out onto racks; peel off waxed paper. Cool cakes completely. Combine cream, corn syrup and butter in heavy large saucepan. Whisk over medium heat until mixture begins to simmer. Add chopped chocolate. Reduce heat to low and whisk until frosting is smooth, about 1 minute; transfer to large bowl. Fill another large bowl with ice. Set bottom of bowl with frosting atop ice. Whisk until frosting is cool and begins to thicken, about 8 minutes. Place bowl of frosting on work surface. Using electric mixer, beat until color lightens and just until frosting becomes thick enough to hold peaks when beaters are lifted, about 2 minutes (frosting will continue to thicken as it stands). Place 1 cake layer, flat side up, on 8-inch-diameter tart pan bottom or cardboard round. If desired, place pan bottom with cake atop 8-inch-diameter cake pan to make simple decorating stand. Top layer with 1 1/2 cups frosting, spreading to edge. Sprinkle evenly with diced toffee. Top with second cake layer, flat side down; press slightly to adhere. Spread thin layer of frosting over top and sides of cake to seal and set crumbs. Spread remaining frosting over top and sides of cake (if frosting becomes stiff, stir gently with spatula to loosen). Stand chocolate bar on 1 short end. Using vegetable peeler and starting at top edge of 1 side, run peeler down length of bar (chocolate will come away from side of chocolate bar in curls). Pile chocolate curls atop cake. Chill at least 2 hours. (Can be made 2 days ahead. Cover with cake dome and keep chilled. Let stand at room temperature 1 hour before serving.)