Heat oven to 350 degrees. Grease and flour two 9″ around cake pans. Use food processor to make 3 cups of graham cracker crumbs. Empty contents into mixing bowl, add baking powder and salt. In a separate mixing bowl put egg yolks, milk, shortening, sugar and vanilla. Mix with hand mixer until smooth. Add to cracker crumbs and mix well. Beat egg whites with mixer until stiff. Fold into cracker mixture. Pour into prepared pans and bake 30-35 minutes. Cool for 5 minutes in the pan, then finish cooling on a wire rack.
2CHOCOLATE BUTTERCREAM FROSTING
Cream butter for a few minutes in a mixer with the paddle attachment on medium speed. Turn off the mixer. Sift 3 cups powdered sugar and cocoa into the mixing bowl. Turn your mixer on the lowest speed (so the dry ingredients do not blow everywhere) until the sugar and cocoa are absorbed by the butter. Increase mixer speed to medium and add vanilla extract, salt, and milk/cream and beat for 3 minutes. If your frosting needs a more stiff consistency, add a little more sugar. If your frosting needs to be thinned out, add additional milk 1 tablespoon at a time.
37 MINUTE FROSTING
In the heatproof bowl set over a saucepan of simmering water, combine sugar, corn syrup, 1/4 cup water, and egg whites. Cook over medium heat, stirring frequently, until mixture registers 160 degrees on an instant-read thermometer, about 2 minutes. Remove from heat using hand mixer beat mixture on high using whisk attachment if you have one until glossy and voluminous, about 5 minutes. Beat in vanilla. Use immediately.
4Cut both cakes in half. Place cake on plate frost tops only with chocolate buttercream. Add another cake layer, then another layer of frosting. Then 3rd cake layer, frost, finish up with 4th cake layer on top. Now frost the outside of cake with the 7 minute frosting. Now for the fun part. Torch the outside of the cake with a butane torch if you have one. I'm not sure if this will work but if you don't have a torch you might be able to use a long grill lighter to toast the frosting. Seems to me like it would work.