Ingredients

• 1 cup 10x (confectioners' sugar)
• 3 large egg whites, at room temperature
• 1/2 cup granulated sugar
• 17 ounces dark chocolate 70% Cocoa
• 1 1/3 cups milk
• 1/2 cup granulated sugar
• 5 ounces unsalted butter
• 3 ounces unsalted butter
• 2 1/2 ounces dark chocolate 70% Cocoa
• 1/2 cup granulated sugar
• 1/2 cup water
• 5 large egg whites, at room temperature
• 4 ounces dark chocolate 70% Cocoa, melted

Instructions

1. Draw three 6 1/2-inch circles on parchment paper at least 1 inch apart. Transfer parchment to baking sheet, circle-side down.
2. Sift 10x sugar. Whip egg whites on stand mixer at medium-high speed. When the whites start to form a peak, gradually add the granulated sugar. Once all the sugar is added, whip to a stiff peak. Take bowl off mixer and fold in the 10x sugar using a rubber spatula. Mix until all the sugar is incorporated.
3. Divide among circles on prepared pans. With an offset spatula or a pastry bag fitted with a plain tip, spread or pipe to evenly fill circles.
4. Chop the chocolate, put in a large bowl. Boil milk and sugar. Pour over chopped chocolate and slowly mix together. Add the butter and mix until incorporated.
5. Keep 9 1/2 ounces for mousse. Reserve rest in refrigerator.
6. For Chocolate and Butter for Chocolate Mousse: Melt butter and chocolate together. Mix together.
7. Melt butter and chocolate together. Mix together.
8. For Italian Meringue: Combine sugar and water in a pot, bring to a boil. Put the egg whites in the bowl of a stand mixer with the whip attached. Using a candy thermometer, cook the boiling sugar, and take the temperature. At 235°F, whip the whites at medium-high speed. When the sugar reaches 240°F, take off the heat and add to the whipping whites in a slow, steady stream. When all the sugar is added, continue whipping until cool. Fold half* the Italian Meringue into the reserved 9? ounces of ganache. Fold the meringue mixture into the chocolate-and-butter mixture.
9. Combine sugar and water in a pot, bring to a boil. Put the egg whites in the bowl of a stand mixer with the whip attached. Using a candy thermometer, cook the boiling sugar, and take the temperature. At 235°F, whip the whites at medium-high speed. When the sugar reaches 240°F, take off the heat and add to the whipping whites in a slow, steady stream. When all the sugar is added, continue whipping until cool.
10. Fold half* the Italian Meringue into the reserved 9? ounces of ganache. Fold the meringue mixture into the chocolate-and-butter mixture.
11. For Chocolate Curls: Thinly spread half the melted chocolate on the back of a 16 1/2 x 12 1/2-inch sided sheet pan with an offset palate knife. Repeat with remaining chocolate on second pan. Let harden. With a firm straight-edge tool about 4 inches long, such as a bench scraper or small ruler, make chocolate curls. Hold tool at about a 45-degree angle against the chocolate and slowly scrape it against the pan to form curls. If the chocolate is too cool, it will crack; if the chocolate is too warm, it will stick to the tool and remain flat. The curls should be 3-4 inches long and about 1 inch in diameter. Reserve curls.
12. Thinly spread half the melted chocolate on the back of a 16 1/2 x 12 1/2-inch sided sheet pan with an offset palate knife. Repeat with remaining chocolate on second pan. Let harden.
13. With a firm straight-edge tool about 4 inches long, such as a bench scraper or small ruler, make chocolate curls. Hold tool at about a 45-degree angle against the chocolate and slowly scrape it against the pan to form curls. If the chocolate is too cool, it will crack; if the chocolate is too warm, it will stick to the tool and remain flat. The curls should be 3-4 inches long and about 1 inch in diameter. Reserve curls.
14. Assembly Line a 7 1/2-inch ring with parchment or waxed paper. Place on flat tray. (The lined ring is optional. Place one meringue disk in the ring. Pour in 1/3 of the mouse. Spread to cover meringue. Repeat with remaining 2 meringue disks and mousse. Smooth top of mousse. Refrigerate until firm, about 3 hours. Melt the reserved ganache until fluid. Remove the ring and paper from the cake. Pour ganache over the cake to cover completely. Cover the top of cake with longer curls and side with shorter curls.
15. Line a 7 1/2-inch ring with parchment or waxed paper. Place on flat tray. (The lined ring is optional. Place one meringue disk in the ring. Pour in 1/3 of the mouse. Spread to cover meringue. Repeat with remaining 2 meringue disks and mousse. Smooth top of mousse. Refrigerate until firm, about 3 hours.
16. Melt the reserved ganache until fluid.
17. Remove the ring and paper from the cake. Pour ganache over the cake to cover completely.
18. Cover the top of cake with longer curls and side with shorter curls.
19. The other half of the meringue is not used for the recipe, but half the quantity is too small to be made in the Kitchen Aid mixer. Additionally, candy thermometers require a certain depth of mixture in order to register. The amount in the recipe requires the pan to be tilted to get enough depth for the thermometer to register — even in a very small pot.