• Preheat oven to 350 degrees. Grease and flour two 8 or 9-inch round cake pans.
• Combine all ingredients in a mixing bowl. Beat on low speed until mixed, then increase mixer speed to medium and beat for about 2 minutes. That batter will be thicker than usual cake mix. Scrape into pans, dividing evenly.
• Bake for 25 to 30 minutes (an 8-inch cake will take at least 30 or until cake tester comes out clean). Let cake cool in pan for 10 minutes, and then turn out onto cooling rack. Let cool while you make the filling.

Fluffy Filling

• In a small, heavy saucepan, not yet over heat, whisk together flour and milk until smooth. Set over medium heat and cook, whisking constantly, until mixture is thick and creamy. Be careful not to overcook or cook it over too high of a heat or you'll get lumps. Scrape into a clean bowl, cover with plastic wrap to prevent a skin from forming, and let cool completely.
• Using your electric mixer, preferably a stand mixer with a whisk attachment, beat butter and granulated sugar until blended. Beat in the vanilla and salt (if using). Beat in the thoroughly cooled flour mixture. Beat until the icing is fluffy and no longer grainy. With a stand mixer and whisk this should take about 5 minutes. The icing will look very curdled at first, but should lose some of the curdled look as the sugar dissolves. If it seems to be curdling too much, remove a couple of tablespoons and melt in the microwave for 5 seconds. With the mixer going, add the melted icing into the bowl. Icing should smooth out.
• Spread the white filling in a thick layer across the top of the cake. Cover with second cake layer, then cover in plastic wrap and chill for 2 hours or until very cold and firm.

Ganache Icing

• Put chocolate and corn syrup in a large bowl. Better yet, if you have one use a Pyrex bowl with a spout.
• Heat the cream in the microwave just until it starts to simmer (or do this over the stove), then pour over the chopped chocolate. Stir until chocolate is melted. Add a pinch of salt if desired. Let stand until icing is thick enough to pour.
• Pour over the chilled cake. The best way to do it is gradually. Pour over a little and spread to the edges and over the sides, then pour on a little more and a little more. The cold cake should help the ganache cling to the side.