Bolo do Caco not 'pão do caco' is a flat bread, traditionally cooked on a Caco, a flat basalt stone slab. An accompaniment or 'apetiser' in most madeiran restaurants...you will find it at all the arraias (festivals) and its usually cooked 'in loco'.
Its a simple recipe, but there are some tricks to get it right...
If you want to give it a go here is a recipe:
1500g of Wheat Flour
1 tea spoon of baker's yeast
1/2 Kg Sweet potato (cooked)
Traditionally the leaven is hand made using flour (1 mug) and yeast and some warm water and allowing it to ferment for a couple of hours until bitter, and then adding it to the mix when making the dough.
The easiest way to make the dough without the leaven is by mixing normal baker's yeast, salt and flour with some warm water.
Cook 1/2 kilo of sweet potato and mash it up, the potato adds the sweetness to the bread...you can add it to the dough mix hot if you wish...
Mix and knead all the ingredients until you get a nice homogeneous dough ball...
Split the dough ball in 4 parts, about a hands width and about 3
centimeters high, and lay them on a flat surface, some distance apart.
Make a cross with your hand over the dough,cover with a towel, and allow to rise...when the cross disappears the bread is ready to cook :D
At this point the bread looks a bit like a cake...that is where the name comes from...bolo means cake.
You probably don't have a caco lying about but you can use a large
frying pan, or a large flat surface (not thin otherwise the bread will
burn rather than cook) over a hot fire. The important thing is for the
flat surface to be hot.
Put some flour down so the dough does not stick to the surface and allow to cook until a thin crust has formed. Flip the bread and do the same on the other side until you get a circular shape like the photo...
Once both sides have a crust you are ready to eat, usually broken with your hands rather than cut with a knife...
Especially good with garlic butter and a espetada :D
Most traditional sandwiched are made with this bread including the 'prego' (steak sandwich), octopuss, espada, carne vinha d'alhos and anything else...