Step #1 ---GLAZE------ 1 c Prune juice 1/4 c Unsalted margarine; (1/2 -stick) 10 oz Bittersweet; (not -unsweetened) or ; semisweet ; chocolate, sliced 24 Walnut halves For Cake: Position rack in center of oven & preheat to 350F.
Step #2 Butter 9-inch-diameter springform pan with 2 3/4-inch-high sides.
Step #3 Dust pan with cocoa powder.
Step #4 Tap out excess.
Step #5 Wrap outside of pan with heavy-duty foil.
Step #6 Place prunes in small bowl.
Step #7 Pour 1 c prune juice over.
Step #8 Set aside to macerate 15 mins.
Step #9 Melt margarine in heavy medium saucepan over low heat/flame.
Step #10 Add chocolate & whisk until smooth.
Step #11 remove this from heat.
Step #12 Add 3/4 c cocoa powder & whisk until smooth.
Step #13 Mix in walnuts & prune mixture.
Step #14 Cool to lukewarm.
Step #15 Using electric mixer, sugar & salt in large bowl at medium speed until well mixed & just beginning to foam, beat eggs, yolks, about 1 min.
Step #16 Add chocolate mixture & stir until well mixed.
Step #17 Transfer batter to prepared springform pan.
Step #18 Set springform pan into large baking pan.
Step #19 Pour enough hot water into baking pan to come halfway up sides of springform pan.
Step #20 Set baking pan in oven & bake cake until top looks dry & crusty & tester inserted into center comes out with some moist crumbs attached, about 1 hr 5 mins.
Step #21 Cool cake in pan on rack 30 mins.
Step #22 place this in refrigerator uncovered & chill overnight.
Step #23 For Glaze: Bring juice & margarine to boil in heavy medium saucepan over medium heat.
Step #24 remove this from heat.
Step #25 Add chocolate & whisk until smooth.
Step #26 Cool until thick but still pourable, stirring every once in awhile, about 45 mins.
Step #27 Line baking sheet with foil.
Step #28 Dip walnuts halfway into glaze.
Step #29 Arrange on prepared sheet & put in the fridge until chocolate is set.
Step #30 Meanwhile, using small sharp knife, cut around sides of cake to loosen.
Step #31 Release pan sides.
Step #32 Set cake on rack.
Step #33 Pour glaze over cake and spread to coat completely.
Step #34 Arrange walnuts, chocolate half at outer edge, around top cake.
Step #35 put in the fridge until glaze is completely set, at least 3 hrs.
Step #36 (Can be prepared 3 days ahead.
Step #37 Cover loosely with foil or cake dome & keep put in the fridged.