Directions - Syrup

1. Combine sugar and water in small saucepan. Stir over low heat until the sugar dissolves.
2. Increase heat and bring to a boil.
3. Remove from heat and mix in whiskey. Let cool to room temperature.

Directions - Mousse

1. Whisk eggs and sugar in large metal bowl.
2. Set bowl over a saucepan of simmering water and whisk constantly until a candy thermometer reads 160°F, about 5 minutes.
3. Remove bowl from over water. Using electric mixer, beat egg mixture until cool and very thick, about 10 minutes.
4. Place chocolate in top of another bowl over simmering water; stir until melted and smooth. Remove bowl from over water and let cool to lukewarm.
5. Combine cream and Irish cream liqueur in medium bowl; beat to stiff peaks. Pour lukewarm melted chocolate over egg mixture and fold together. Fold in cream mixture.
6. Cover and chill until set, at least 4 hours or overnight

Directions - Cake

1. Preheat oven to 350°F. Butter 9-inch diameter springform pan with 2 ¾ - inch high sides. Line bottom with parchment paper.
2. Using electric mixer, beat eggs, sugar, espresso powder and salt in a large bowl until mixture thickens and slowly dissolving ribbons form when the beaters are lifted, about 8 minutes.
3. Sift 1/3 of the flour over and gently fold into the egg mixture. Repeat 2 more times being careful not to over-mix.
4. Pour batter into the prepared pan. Bake until a tester comes out clean, about 35 minutes. Cool cake completely in pan on rack.

Directions - Assembly

Cut cake into three layers. Put syrup on the bottom layer and spread 2 cups of mousse over. Repeat for next two layers. Spread excess mousse over the sides and sprinkle the chocolate slivers all over the cake. Keep cake refrigerated.