Marble Gugelhupf Cake

Okay, this cake is probably not only popular in Germany but in many places around the world. It was the kid's birthday cake in the 70ties when I grew up. It's easy to make and also easy to transport and to shove candles in. Usually in Germany you would only sieve some icing sugar on top of the cake but I think kids will love a chocolate glaze even more and it gives the cake a beautiful shiny look. I have included a recipe for the glaze as well.
The original Gugelhupf cake is ususally made from a yeast dough but in Germany it's only referred to as a marble cake.

Here is the recipe:
Serves 10

Cooking oil spray for the tin
200 g butter, softened
250 caster sugar
3 eggs
300 g plain flour
3 teaspoons baking powder
200 ml buttermilk
60 g almond meal
2 tablespoons cocoa powder
Extra 2 tablespoons buttermilk

Extra: icing sugar or
chocolate glaze: 3 tablespoons cream, 100 g dark or milk chocolate melts

1. Preheat oven to 180 degree. Grease a Gugelhupf tin (best to use cooking oil spray).
2. Put butter and sugar in a bowl and beat until pale and creamy. Add eggs, 1 at a time, beating continuously. Mix flour and baking powder into a medium bowl. Gradually add flour mixture to batter alternating with the buttermilk, stirring, until combined. Add almond meal and stir to combine.
3. Put 1/3 of the cake mixture in a large bowl, then stir in cocoa and extra buttermilk. Spoon remaining cake batter into prepared tin. Top with chocolate batter. To create marble effect, swirl a fork gently through batter.
5. Bake for 50-60 minutes or until cooked when tested with a skewer. Cool in tin for 5-10 minutes before turning out onto a wire rack to completely cool.
6. Sieve icing sugar over the cake or make a glaze: melt cream and chocolate in a heatproof bowl over a saucepan of simmering water. Stir until smooth. Drizzle glaze over cake and let set. Decorate with sugar sprinkle if you wish.