Bicarbonato is baking soda. Horno de polvo is baking powder. Flor is powdered sugar and chocolate amargo is unsweetened cocoa for baking-there is also a dulce(sweet) version available.
Then we went to Lider, which is something like a Chilean Kmart. Lider has groceries, clothes, shoes, bags and bags of dog food, sets of dishes, shampoo... And I found a rectangular cake pan, a Pyrex measuring cup with both US & metric measures, a loaf pan for banana bread and a pie plate!
And the chocolate cake turned out just fine. I'll make some adjustments on the oven temperature and time next attempt but we were quite happy.