Recipe(tried): Moist Chocolate Genoise

burm,
I have 2 chocolate cake recipes that might suit your need. Here is the one from "The Cake Bible". It is used for a Swiss Black Forest cake and some others. You can easily double the amount to make it a tall, 4-layer cake and fill the cake with your favorite cream. But in this case, you will need two 9" can tins. Another one was posted by Csally/Wv. You should be able to located it under the title "Chocolate Rasberry Mousse Cake". (I recently made it for a friend's birthday and everyone loved it in the party. Unfortunately, I was just diagnosed of migraines and can't enjoy chocolate cakes anymore so I didn't eat that cake myself.) But I believe you will enjoy these two cakes. I know that your dad doesn't like the one with Mayo or else Julie C/South Africa has a great recipe that my family really like...
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Moist Chocolate Genoise
one 9-inch springform pan or cake tin (must be straight on the sides), greased, bottom lined with parchment and then greased again and floured.
Ingredients:
4 oz. Bittersweet chocolate
4.125 oz(1/2 liquid cup) boiling water
4 large eggs (7 oz. Weight without shells)
3.5 oz. Sugar (regular white sugar is fine.)
2.625oz (75g/3/4 cup) sifted cake flour

Preheat the oven to 350F. Ina heavy saucepan bring the chocolate and water to a boil over low heat, stirring constantly. Simmer, stirring, for 5 minutes or until the chocolate thickens to a pudding like consistency. (It will fall from the spoon and pool slightly before disappearing.) Cool completely.
In a large mixing bowl, beat the eggs and sugar with the whisk beater on high speed for 5 min or until triple in volume. ( a hand beater may be used but it will be necessary to beat for least 10 min.)
Sift the flour over t he egg mixture and fold it in gently but rapidly with a slotted skimmer or a large rubber spatula until dome of the flour has disappeared. Repeat with the remaining flour until all flour has disappeared. Fold in the chocolate mixture until incorporated.
Pour immediately into the prepared pan. (It should be about 2/3 full) and bake 30 to 35 min or until a tester inserted in the center as easily as it does when inserted closer to the sides. The cake rises to the top of the pan during baking and will lower slightly when done, pulling slightly away from the sides. Avoid opening the oven door before the min. time or the cakes could fall.
Loosen the sides often cake with a small metal spatula and unmold at once onto lightly greased rack. Re-invert to cool. The firm upper crust prevents falling. Trim the top and bottom crust removed (very important or else it will form "crusts" in between the cream after it's soaked in the syrup) and split in half horizontally to make (2) " layers.