Does anyone have a recipe for those cakes found in japanese restaurants?

I love those cakes you get at the japanese or chinese buffets. The small, light, fluffy, squares. Usually they have a bunch, chocolate, banana, mocha, green tea, strawberry etc. Anyone know recipes for these or where I could find them?Does anyone have a recipe for those cakes found in japanese restaurants?
JAPANESE CHOCOLATE CAKE





1 stick butter


3 1/2 tbsp. cocoa


1/2 c. oil


1 c. water


2 c. sugar


2 c. flour


Pinch salt


2 eggs


1 tsp. soda


1/2 c. buttermilk


1 tsp. vanilla





In pot put butter, cocoa, oil and water; bring to a boil. Sift together sugar, flour, and salt; pour chocolate mixture over and beat. Add 2 eggs.





While beating, let soda dissolve in buttermilk. Add vanilla, then add soda and buttermilk. Bake in greased 13x9 pan at 400 degrees for 20- 25 minutes.





JAPANESE CHOCOLATE ICING:





1 stick butter


3 1/2 tbsp. cocoa


6 tbsp. milk


1 box powdered sugar


1 tsp. vanilla





Put in pot butter, cocoa, milk and bring to boil in saucepan. Add 1 box powdered sugar. Beat until smooth. Add 1 cup nuts (optional) and 1 teaspoon vanilla. Spread on warm cake.