Mini Blueberry Swiss Roll

I've been wanting to make this Indonesian-type of swiss roll with blueberry filling, after a friend of mine gave me one, imported from Indonesia a couple of months ago. Yes, I liked it that much that I wanted to replicate it. The only thing that held me back was the fragrant blueberry filling they use. I couldn't find it here, so I brought some from Indonesia when I was visiting two months ago, and it has become one of my favorite ingredients :).

I'm usually all for light and spongy cake, but Indonesian swiss roll is anything but light. It's made with sponge-cake method, but uses a lot more egg yolks compared to the amount of egg whites, relatively very little flour and a good amount of melted butter. The egg yolks make the texture dense, but very soft just like most of other Indonesian delicacy and the butter makes it really moist. If sponge cake usually is just used for a base, concentrating more on the flavor of the filling, for Indonesian-type of cakes such as this swiss roll, "Lapis Surabaya", thousands of layers cake (a.k.a lapis legit), the cake itself is the highlight. People want to taste the strong butter flavor, and the softness of the texture. That is why this kind of cake usually doesn't have a lot variation on the filling. The traditional filling would be a very thin layer of jam, or a thin layer of buttercream and sometimes a thin layer of ganache.

For cheese filling swiss roll, I prefer the lighter version of the cake. It's not as light as those you would get in a Chinese bakery, but definitely lighter than this one. It's more like Indonesian sponge cake, very soft but a little lighter. The buttercream and cheese filling would be way too heavy for this dense yet soft cake.

So, here is the mini version, made in a 10x10 in square pan. I was really satisfied with the result. It has anything that Indonesian swiss roll is supposed to be. Not to mention the very fragrant blueberry filling inside, yumm....