Welcome to the Cake Decorators Q&A
10″ Square madeira cake
What temperature and how long do I cook a 10" X3" deep madeira cake
It really depends on which recipe you are using. Not all Maderia cakes take similar times.
If you are using Mrs Jones'recipe from this site, recommended baking temperature is 150c or 130c fan. Times will vary as all ovens are different, so your oven may take longer or less time.
For a 10" square, I suggest approximately 2hrs 20 minutes.
About two-thirds of the way through the baking time, Madeira cakes begin to dome in the centre. This would be the time to check the centre of the cake with a wooden skewer. If the skewer comes out with wet crumbs, continue baking and check after 10 minutes and continue baking if still wet. If the crumbs are slightly wet, check after 5 minutes and keep checking until done. Let your eyes and nose guide you.
The corners of square cakes are vulnerable to over-browning. To prevent this, I recommend double lining the cake tin, this might very slightly add to the baking time.
Hope this helps. 🙂