Preheat oven to 350 degrees F. Grease and flour 2- 9 inch cake pans. Ina a large bowl, mix the flour, sugar, cocoa powder, baking soda and salt
Beat in the shortening with an electric mixer on low speed. Beat in milk, coffee and vanilla until combined. Increase speed to high and beat for 2 minutes. Add the eggs; beat for 2 minutes
Pour the batter into the prepared pans; smooth with a spatula. Bake the cakes in the middle of the oven until a toothpick inserted comes out clean, 30 - 35 minutes. Cool the cakes in the pans for 5 minutes, then turn the cakes onto wire racks to cool completely.
For the frosting, combine the cocoa powder, butter, corn syrup, vanilla, and salt in a large bowl. Beat on medium speed for 2 minutes. Add the warm water; mix well. Beat in the confectioners' sugar in 2 batches. Beat until smooth.
Place one layer top side down on a large flat plate. Spread with 1 cup of the frosting; sprinkle with 2/3 cup walnuts. Top with the remaining cake layer, top side up. Frost the top and sides with the remaining frosting, swirling with a small spatula. Garnish the cake with the remaining walnuts.