I prove mine in a basket, but even a colander lined with a well floured cloth will do. This shapes the dough, and if you think that the dough is too soft, after it has proved, place it covered in the fridge for 30mins to stiffen the dough. Remove it and lace it immediately into the heated oven. I was told this by a well known baker, though I have never needed to do it. If in doubt, give it a try. Ordinary yeast free form cobs shouldn't need this, but this is from the book "The Pink Whisk to Breadmaking" by Ruth Clemens.
5 Flatten the dough into a rough circle. Taking the outside edge of the dough fold it in to the middle and work in this way all around the outside edge until you get back to where you started and can fold in no more! 6 Flip the dough over so that the seam is underneath. Gently cup your hands around the ball of dough and start to tighten the dough again, moving your hands down and underneath it, repeating until the dough feels tight like a coiled spring. Repeat the tightening action, gently encouraging the dough into a round shape, all the time keeping the seam underneath. The shaping is important in getting a free- form loaf to rise upwards and keep its shape rather than flowing outwards. 7 Set the loaf onto a baking sheet lined with baking.
Give this a try, hope it works.
Así es la vida.