A friend posted a link to this cake on FB. It's from Bon Appetit. I changed a few things like I used my own cake recipe. It's a lot of work but worth it.
Irish Cream Chocolate Cake

Mousse:
Mix and microwave until 160ºF stirring every 10 seconds:
4 large eggs
1/3 cup sugar

Beat 10 minutes until cool.

Melt and cool to lukewarm:
12 oz semisweet chocolate

Gently stir chocolate into egg mixture.

Combine and beat until stiff peaks:
1 1/2 cups chilled whipping cream
1/4 cup Irish cream liqueur

Fold chocolate mixture into cream and refrigerate at least 4 hours.

Cake:
Prepare a Devil's Food Cake and use three 9" rounds

Spread half the mousse on a cake then cover with another cover with rest of mousse and place 3rd cake on top. Ice cake with Chocolate Buttercream (about half the recipe). Refrigerate cake while making chocolate bands.

Chocolate Bands and curls:
Mix and melt:
6 oz semisweet chocolate
1 oz butter

Cut strips of parchment paper that are about 18" long and slightly wider than the cake is tall. Spread chocolate on strips then refrigerate on metal cookie pans until firm (about 5 minutes). Carefully place bands on cake while trying touch/warm chocolate. Hold band against cake with a knife and peel paper. Use left over chocolate to make curls. Spread a thin layer of chocolate on parchment paper. Refrigerate until firm. Using spatula peel chocolate off encouraging it to curl. Chocolate softens very fast at room so return to fridge as needed.