Making kozhukattai is an art, especially making the outer cover. It takes practcice and time to make this right. I have tried to explain it with pics as clear as possible. Hope it helps.
While making the outer cup (we call it soppu in tamil), try to apply oil in your palm before shaping it. Also if you feel the shape is breaking, it might be because the dough has become dry. Moisten your hand and knead it once more.
This post is for Blogging Marathon 42 under the theme "Ganesh Chathurthi Festival". Check out the Blogging Marathon page for the other Blogging Marathoners doing BM# 42 here.