A great flavorful cake!
Set over to 350 and grease two 8-9" cake pans.
Mince 1 vanilla bean and place into 1/2 C boiling water and let steep.
Mix together 1 C white flour, 3/4 C cocoa powder, 1.5tsp baking powder, 1 tsp cinnamon and .5 tsp salt.
Separate four eggs. Mix 5/8 C white sugar with 5/8 C brown sugar with the vanilla water and the yolks and 1/4 C neutral oil (canola, veg, etc). Add flour/cocoa mixture and mix well.
Beat whites to stiff peaks and fold by hand into batter.
divide batter into pans, bake for 25 minutes. Turn cakes out onto wire racks or cutting boards to cool.
Heat 1/2 stick butter until melted in stove or microwave. zest 1/2 - 1 orange rind into orange and mix with 10X confectioners sugar (or grind your own in the coffee/spice grinder) until thick. Add about 1/4 C milk and a bit more 10x confectioners until the frosting is drippy but a fingertip will hold about a tsp of frosting.
Once cake is cooled, spread frosting on the bottom layer, and place the top layer on top. Frost the top and sides. Serve - especially good with whipped cream or a good vanilla gelato.