In a large bowl, combine the cassava flour, salt, and baking powder (if using).
Gradually add water to the dry ingredients, mixing until a smooth dough forms. The dough should be pliable but not too sticky. Adjust the water as needed.
Divide the dough into small balls, about the size of a golf ball.
On a lightly floured surface, flatten each ball into a thin, round disk, about 1/8 inch thick.
Heat a skillet or griddle over medium heat and lightly grease with butter or oil.
Place the flattened dough disks onto the hot skillet and cook for about 2-3 minutes on each side, or until golden brown spots appear and the kasav is cooked through.
Remove the kasav from the skillet and let cool slightly before serving.
Enjoy your meal!