Tangerine butter cake

Looking for a simple cake recipe, I found this golden and delicious cake - it is the perfect companion for a cup of tea; it was a great way to use up the sweetened condensed milk left from the cheesecake making, as well a a wonderful way to put to good use some tangerines I'd had in the fridge for more than one week.

Tangerine butter cake
slightly adapted from Dan Lepard's column at the