When I went to New York for the first time last summer, I was actually shocked over the portion sizes in some restaurants, although of course I knew  what to expect.

And the same thing happened to me with this cake. It is an American recipe so I expected a large cake. But not this giant. Oh well, it doesn’t matter as it went down a treat and disappeared very quickly at the office despite its size.

And no wonder. The sponges are very light and super moist (thanks to the buttermilk in the batter). And the very strange frosting, consisting of little else but dark chocolate and sourcream, is neither too rich nor too sweet.

All in all, I would say this is a pretty perfect cake!

Sponge cake with buttermilk, 2 large round cakes

Adapted from Smitten Kitchen’s recipe.

480 g plain flour

2 tsp baking powder

1 1/2 tsp bicarbonate of soda

1 tsp salt

225 g unsalted butter, softened

400 g caster sugar

2 tsp vanilla

4 large eggs, at room temperature

475 ml buttermilk 

Preheat the oven to 175C. Grease to springforms, about 22 cm in diameter and cover with a round of baking parchment in the bottom. 

Mix flour, baking powder, bicarb and salt in a bowl. Beat butter and sugar creamy in a mixing bowl with an electric mixer. Add the vanilla. Then add the eggs one at the time. Mix well in between each and scrape down the sides. Then add the buttermilk and don’t over-mix. Add the flour mixture in batches. 

Divide the batter between the two tins. Bake for 30-35 minutes or until a toothpick comes out clean. Leave to cool in the tins and then let cool completely on wire racks.

Chocolate frosting with sourcream, enougn to cover a large cake with two sponges

Adapted from Smitten Kitchen’s recipe.

425 g dark chocolate, roughly chopped

530 ml sourcream – N.B! at room temperature!

ca 60 ml corn syrup, to taste

3/4 tsp vanilla

Melt the chocolate over a bain marie. Leave to cool until at room temperature. 

Mix sourcream with corn syrup and make sure it is at room temperature. Add the tepid chocolate in batches. In case of lumps use a wire whisk and they should disappear. Leave to set in frdge for about 30 minutes or until spreadable without being runny. 

Place one sponge on a cake plate and cover it with frosting. Place the other cake on top and cover the top and sides with frosting. Keep in fridge until serving.