Preheat oven to 350 degrees.
Grease and flour two 9" round cake pans.
To prepare the cake, in a medium bowl, combine the flour, cocoa, baking soda and salt.
In a large bowl, with electric mixer on medium, beat butter and sugar until light and fluffy, about 10 minutes.
Add eggs, one at a time, beating well after each addition.
Add vanilla.
With mixer on low, alternately beat in flour mixture and water.
Pour batter into pans.
Bake for 30 - 35 minutes until toothpick inserted in center comes out clean.
Cool in pans for 10 minutes.
Remove from pans: cool on rack.
Using a sharp knife, split each layer in half horizontally.
Spread 3 layers with the preserves.
To prepare the butter cream filling, beat butter until light and fluffy Alternately beat in sugar, cocoa and milk.
Add vanilla.
Spread 1/3 of the butter cream over each layer with apricot preserves.
Stack layers, ending with the plain layer.
To prepare the glaze, in a small saucepan, mix sugar, cocoa, heavy cream and water.
Cook over low heat, stirring, until smooth.
Bring to a boil: Boil for 1 minute.
Cool slightly.
Place cake on rack over wax paper.
Pour glaze over the cake, spread- ing to evenly coat.
Chill 30 minutes or until set.
Garnish with whipped cream piped around the top edge and spot the chopped pistashios around the top of the whipped cream.
