Wrap the sweet potatoes (with the skin) in foil and bake them in the oven for 30 minutes at 180ºC (350ºF) or until the sweet potatoes are fork-tender.

Pour the yeast and the salt into the water and let it sit for 10 minutes at least.

Take the sweet potato out of the oven and let it chill. When it’s completely cold, take the inner part of the potatoes out and smash them into a puree.

Take a big bowl (or you can use a table that is cleaned) and pour the flour forming a mountain with a small hole on top like a volcano.

Pour the water and the mashed sweet potatoes in the center of the flour and knead until you get a homogeneous dough that doesn't stick to your hands.

Let the dough rest for 30 minutes until the dough doubles in size. Cut into 5 pieces and let it rest another 30 minutes.

On a stove, heat a cast iron pan over medium heat until the pan is hot. Take one of the dough pieces and form a disc. Cook it in the pan for 10 minutes each side until the bolo do caco is ready.

For the Garlic Butter: Mix the butter, the coriander, and the garlic.

Cut the bolo do caco in half lengthwise and spread with the butter. Serve while it is warm, and enjoy!