Grease a 6" or 8" springform pan and press cookie dough into the bottom and up the sides in a 1/4 inch layer. Bake until it's golden, but not completely cookie-like. It will solidify as it sets and it will be baked again. We don't want any burnt cookies on our hands!
Preheat oven to 350F. Add all the cheesecake layer ingredients into a large bowl and beat until smooth. Pour over the cookie crust layer and bake 30 minutes, or until the sides of the cheesecake are set but the center is just a bit wobbly. Cool to room temperature and refrigerate at least 6 hours.
Combine the chocolate and water in a heatproof bowl set over a pan of barely simmering water. Heat until the chocolate is almost melted, stirring occasionally. Remove from the heat and stir until the mixture is smooth. Cool to room temperature.
In a clean, dry bowl whip the egg whites and the salt on medium-high speed until stiff peaks form.
Stir the egg yolks into the cooled chocolate mixture. Add one third of the whipped egg whites to the bowl with the chocolate and fold gently to lighten up the mixture. Fold in the remaining egg whites gently with a spatula just until no visible streaks are left. Smooth over the top of the cheesecake and refrigerate at least three hours before serving.