Chocolate Mousse Trifle

http://chefdruck.com/2013/04/chocolate-mousse-trifle/

Ingredients
For the meringue layers
4 large egg whites
1 ¼ cups sugar

For the chocolate mousse
9 egg whites
1/4 cups of granulated sugar
375 grams (13 oz) of bittersweet chocolate
6 egg yolks
225 grams of butter, cut into small pieces at room temperature
1/2 cup of powdered sugar


First, make the meringue layers.
Preheat to 400 degrees Fahrenheit. Line two baking sheets with waxed paper or silpat.
Beat egg whites in large bowl until soft peaks form. Gradually add 1 ¼ cups sugar, beating until meringue is stiff and very shiny. With that much sugar, it will not completely hold peaks when you pull out the beaters, but it should keep some shape and not become completely flat.
Using a soup spoon, spread meringue evenly on 2 prepared baking sheets in 4 circles the same circumference as the trifle bowl. No need to be too exact about this. A messy trifle is beautiful to behold. As my trifle bowl flares out, I made the circles uneven, smaller ones for the bottom, and bigger ones as you go up.
Bake until pale golden, about 8 minutes. Reduce oven temperature to 325°F. Bake until meringue is slightly firm to touch on top but soft inside, about 8 minutes longer.
Let the meringue cool for 30 minutes to an hour at room temperature. While the meringue cools, make the chocolate mousse.
Melt the chocolate in the microwave. Break it into coarse chunks and microwave it for 30 second segments, mixing every 30 seconds. The chocolate should melt beautifully within 2 minutes.
Beat in the room temperature butter pieces. The consistency should be like pudding. Fold in the powdered sugar.
Add the egg yolks, making sure the chocolate mixture is relatively cool to not curdle the eggs. Set aside.
Beat the egg whites until stiff, adding the 1/4 cup of sugar half-way through to keep them firm.
Pour the chocolate mixture on top of the egg whites, and fold it carefully together, rotating the bowl a quarter turn after every fold. You want to be very gentle to maintain as much of the air as possible. But the two will be hard to combine, so keep on mixing, softly softly, until you cannot see any white clumps of beaten egg whites.
Find a see through bowl and layer the chocolate mousse and meringue slices, beginning with the chocolate mousse and finishing with the meringue. Drizzle a little cocoa powder on top for decoration.
Chill for at least two hours before serving, or better yet, overnight