Chocolate Cake, Flourless, La Bete Noir​ Cake

Preheat oven to 350*F. Butter 9 inch diameter springform pan. Line bottom of pan with parchment paper round. Wrap 3 layers of heavy-duty foil around outside of pan, bringing foil to top of rim. Combine water and sugar in a small saucepan. Bring to boil over medium heat, stirring until sugar dissolves. Simmer 5 minutes. Remove from heat. Melt butter in large saucepan over low heat. Add chocolate and whisk until smooth. Whisk sugar syrup into chocolate; cool slightly. Add eggs to chocolate mixture and whisk until well blended. Pour batter into prepared pan. Place cake pan in large roasting pan. Add enough hot water to roasting pan to come halfway up sides of cake pan. Bake cake until center no longer moves when pan is gently shaken, about 50 minutes. Remove from water bath; transfer to rack. Cool completely in pan.