My mother made all our birthday cakes till pretty much our teenage years. The cake was almost always based on a pound cake principle and one of the most frequent variation in our house was the Marble Cake. We used to all gather around her as she measured the maida, sugar and butter against the weight of eggs using an old school tarazu. It's a distinct memory so this cake is special.
We too started off at the pound cake ratio but veered off slightly as we wanted distinct flavors and textures between the vanilla and chocolate component. This is a rich pound cake with a moist, tender and dense crumb. The vanilla part is buttery and vanilla-y while the chocolate part is super chocolatey and slightly bitter, in a good way. Eat it at room temperature or slightly warm and you will get enveloped in nostalgia (if you were born in the right decade!)