Preheat oven to 375 degrees F. Grease bottoms only of 2 9-inch round cake pans. Line the bottom of pans with parchment paper. Grease parchment paper. Be careful and do not grease the sides of the pans. Set pans aside. In a small bowl, whisk together flour, baking soda, salt, ground pecans, and cocoa.

In a large bowl, beat egg yolks at high speed of an electric mixer. Gradually add 1/2 cup sugar and beat until mixture is thick and pale. Add flour mixture to yolk mixture alternatively with water, beginning and ending with flour mixture. Stir in vanilla.

In a medium bowl, using clean beaters or whisk beater, beat egg whites at high speed of an electric mixer until foamy. Gradually add 1/4 cup sugar and beat until stiff peaks form. Fold egg whites into batter. Pour batter equally into prepared pans. Bake for 16 to 18 minutes or until a wooden pick or cake tester comes out clean.

Cool pans on wire racks for 10 minutes. Remove cakes from pans and let cool completely on wire racks.

Combine powdered sugar and cocoa in a large mixing bowl. Gradually stir in whipping cream. Add vanilla. beat at low speed of an electric mixer until blended. Beat at high speed until stiff peaks form.

Note: do no make this until after you have assembled the cake. This is the last step in the process.

Combine cocoa, water, and butter in a medium saucepan. Cook over medium heat, stirring constantly, until mixture thickens. Remove from heat and stir in powdered sugar and vanilla. Pour and spread over top of cake.

Split cake layers in half horizontally to a make 4 layers. Place 1 cake layer on a serving plate. Spread 1 cup of frosting on top of layer. Repeat procedure with second and third cake layers and 2 additional cups of frosting. Top stack with fourth layer. Spread remaining frosting on sides of cake. Gently press toasted chopped pecans into frosting. Pour and spread chocolate glaze on top. (Some may drip down the side). Refrigerate cake if not serving immediately. Keep leftovers refrigerated.