Cocoa Mantle Crust Earth Forming

In Science we had to try and recreate the earths crust breaking and mantle something or something and this is what the video showed:

I think plates move around and then it gets uneven so one will rise up and one might sink, then it cracks, and all the movement causes earthquakes, or an eruption of all the lava or something thats underneath and thats what happens. 

https://sites.google.com/site/tectonicswebsite/tectonic-processes

Ours worked nice but it didn't crack first like in the video. 

The milk bubbling underneath represents the magma, lava stuff.

The cocoa represents the earths crust and how it cracks and formed little islands such in the last picture they represent the continents.