Preheat oven to 300 degrees Fahrenheit. Cover a large baking sheet with Gefen Parchment, cut to fit.

Take an eight-inch round pan and trace two circles on the parchment using a dark pen or permanent marker. Turn the parchment paper over. Set aside.

In a medium mixing bowl, place the ground almonds, confectioners’ sugar, and cocoa, and whisk together. Set aside.

In a large mixing bowl, place the egg whites.

Using the wire whisk attachment, start beating the whites on low/medium speed until they start to look foamy, about 45 seconds. Turn machine to low and add the salt.

Turn speed up to medium for a few seconds and then to high, and beat until soft peaks form. To check this, once the whites start to look thick, stop the machine and lift up the wire whisk beater. If the peak goes up then bends over slightly, your whites are ready for the sugar.

Turn the machine on low and add sugar in four parts, counting to 10 after each addition before adding the next part.

Turn the speed back up to high and beat another one to two minutes, until the whites are glossy. Add the almond extract and mix on low for a few seconds, until incorporated.

Scoop up about one third of the whites and add to the dry ingredients. Use a silicone spatula to mix the whites into the dry ingredients. This takes a few minutes.

When mostly mixed in, add another third of whites and this time mix more gently until incorporated. Add the final third of whites and fold in very gently.

Scoop up and divide the batter between the two circles on the parchment paper. Use the spatula to spread almost to the edges of the circle, by moving the spatula back and forth and turning the baking sheet until they are as even as you can make them.

Bake for one hour. Turn oven off and let sit in oven another hour. Remove and let cool completely. May be made four days in advance and stored at room temperature.

Melt the chocolate either over a double boiler or in the microwave for one minute, stir, melt 45 seconds more, stir, melt 30 seconds more, stir, and then melt in 15 second increments until melted and smooth.

Add the egg yolks and almond extract if using and whisk vigorously; the mixture may be pasty, but do not worry about that.

In a separate bowl, beat the egg whites with an electric mixer on high speed until stiff peaks form. Turn the speed to low and add the two tablespoons of sugar in two parts, counting to 10 between additions, and then turn the speed up to high and whisk another minute. Fold the stiff egg whites into the chocolate mixture in two parts.

Rinse the bowl. Using the same bowl and whisk attachment, whip the whipped topping until stiff. Fold into the chocolate mixture, and mix well.

Preheat oven to 325 degrees Fahrenheit. Place the slivered almonds on a cookie sheet and bake for 15–20 minutes or until toasted and fragrant. Let cool.

Place one dacquoise circle, top side up, on a serving plate. Scoop up half the mousse and spread on the circle, leaving about a quarter-inch border. Place the other circle on top, top side up. 

Spread the remaining mousse, also leaving a quarter-inch border. Sprinkle with the toasted almonds.