Step 1
Preheat oven to 350 degrees F (175 degrees C). Grease a 10-inch bundt pan.
Step 2
To Make Filling: Beat egg white with 1 teaspoon vanilla until soft mounds form. Add 1/2 cup sugar gradually beating until stiff peaks form. Stir in coconut and 1 tablespoon flour. Set filling aside.
Step 3
Dissolve the cocoa in the hot coffee. Separate the three eggs setting the yolks aside. Beat the egg whites until soft mounds form. Gradually beat in 1/2 cup sugar until meringue stands in medium-stiff peaks.
Step 4
Combine the sour cream and the baking soda. Beat remaining 1 1/4 cups of the sugar shortening egg yolks salt 1 teaspoon vanilla and 1/2 of the of the cocoa mixture until light and creamy about 4 minutes. Stir in 2 cups flour the sour cream mixture and the remaining cocoa mixture; blend well.
Step 5
Fold about 1/3 of the beaten egg whites into the batter to lighten it; gently fold in remaining egg whites.
Step 6
Turn 1/2 of the chocolate batter into the prepared pan. Place 1/2 of the coconut mixture on top. Cover with the remaining chocolate batter then the remaining coconut mixture.
Step 7
Bake in preheated oven until a tester inserted in the center of the cake comes out clean 55 to 65 minutes. Let cake cool completely before removing from pan and icing.
Step 8
To Make Icing: Combine 2 cups sugar and 1/4 cup cocoa powder; transfer to a saucepan. Add butter corn syrup and milk. Bring to boil over medium heat stirring frequently and let boil for 1 minute. Do not overcook! Remove from heat let cool and stir in 1 teaspoon vanilla. Beat icing until it is at a soft spreading consistency; glaze cake.