To prepare sauce, combine the first 3 ingredients in a medium saucepan, and bring to a boil. Reduce heat, and simmer until reduced to 2 cups (about 30 minutes). Chill.
Preheat oven to 350°.
To prepare cake, place pistachios in a food processor; process until finely ground. Sprinkle ground pistachios over bottom of a 9-inch springform pan coated with cooking spray.
Combine 1 cup sugar and water in a medium saucepan; bring to a boil. Remove from heat; stir in chocolate and salt, stirring until chocolate melts. Add cocoa, stirring with a whisk until well blended. Add eggs, 1 at a time, stirring well after each addition. Stir in extracts.
Beat egg whites with a mixer at high speed until foamy. Gradually add the remaining 1/4 cup sugar, 1 tablespoon at a time, beating until stiff peaks form. Gently stir one-fourth of egg white mixture into chocolate mixture; gently fold in remaining egg white mixture. Spoon mixture into prepared pan. Bake at 350° for 25 minutes or until wooden pick inserted in center comes out nearly clean. Cool to room temperature; run a knife around outside edge. Serve with sauce.