Preheat the oven to 350°F. Lightly grease and flour (or grease, then line with parchment, then grease again) two 8" x 2" round cake pans. Note: These pans need to be at least 2" tall; if you have non-standard, shorter 8" pans, substitute 9" round pans., To make the cake: Whisk together the dry ingredients. Add the eggs, oil, vanilla, and water, beating until smooth. Pour the batter into the prepared pans., Bake the cakes for 35 to 38 minutes (a bit less if you use a 9" pan), or until a cake tester inserted into the center comes out clean. Cool the cakes in the pan for 15 minutes, then turn them out of the pans to cool completely on a rack., To make the filling: Combine the chocolate and cream in a microwave-safe bowl, and heat until the cream is very hot, and the chocolate very soft. Stir to melt the chocolate completely, reheating very briefly if necessary., Now you have a choice. You may either flavor the filling all one flavor, or use a different flavor for each layer of filling. For all one flavor, use 3 tablespoons of your favorite liqueur — Frangelico (hazelnut), Kahlua (coffee), or Framboise (raspberry) are all good choices. Or try 2 tablespoons rum. Alternatively, add 1 tablespoon espresso powder; or flavor to taste with a bottled extract (coconut, peppermint, cherry, almond...) To mix and match flavors, divide the filling into three parts, and flavor each differently to taste, with an extract; or with about 1 tablespoon liqueur for each flavor., Divide the cooled layers in half horizontally, to make four layers. Place one layer on a serving plate, and spread with filling. Repeat with the next two layers. Top with the final cake layer. Note: The filling should be soft but not soupy. If it seems too runny to sit nicely atop the layers, simply let it rest at room temperature (or in the fridge, for quicker results) until it thickens up a bit., To make the icing: Combine the chocolate and cream in a microwave-safe bowl, and heat until the cream is very hot, and the chocolate very soft., Stir to melt the chocolate completely, reheating very briefly if necessary. Pour and spread the icing over the top of the cake, letting it drip over the edges and down the sides., Once it's done dripping, you may smooth the sides with an icing spatula, if desired. Allow the cake to rest, covered with a cake cover (or a big turned-over bowl) until the chocolate is set; overnight is good, though several hours are sufficient.