- 10 large matzohs
- 1 cup strong brewed coffee (or 6 tablespoons instant coffee granules dissolved in 1 cup of hot water), cooled
- 23 ounces parve bittersweet chocolate, divided
- 8 large eggs, separated
- 1 cup sugar, divided
- 1 cup (2 sticks) margarine, at room temperature
- Line a 9 x 13-inch pan with 2 pieces of plastic wrap that are large enough to drape over and cover all of the sides.
- Break the matzoh pieces in half. Pour the coffee into a shallow pan and add the matzoh pieces, turning them over so that each piece becomes soaked with the coffee. Set aside.
- To make the Mousse: Break 21 ounces of the chocolate into small pieces and melt either on the stovetop or in the microwave.
- Meanwhile, in a large bowl, beat the egg yolks with 3/4 cup of the sugar. Add the softened margarine and beat with an electric mixer on medium-high speed or vigorously by hand with a whisk until combined. Add the melted chocolate and beat again.
- In a separate bowl, with an electric mixer on high speed, beat the egg whites until they start to stiffen. Turn the speed to low, add the remaining 1/4 cup of sugar, and then turn the speed back to high and beat until very stiff, about 1 minute more. Fold the whites into the chocolate mixture.
- Spoon about 1/5 of the mousse into the prepared pan to cover the bottom. Add 3 to 4 matzoh halves to cover the mousse in 1 layer. Add another 1/5 of the mousse to cover the matzoh and then another layer of matzoh. Repeat until you have used all the matzoh. There should be 4 to 5 layers, depending on the size of your matzoh pieces. The last layer should be the mousse. Cover with plastic.
- Place in the freezer for a minimum of 3 hours or overnight. Place in the refrigerator 1 hour before serving.
- To serve, unmold the pan onto a large platter and peel off the plastic wrap. Use a grater or vegetable peeler to shave the remaining 2 ounces of chocolate on top of the mousse. Cut into 20 pieces.