I think a Ferrero Rocher is a good fit. The solid core is the hazelnut, the molten core is the Nutella, the rocky crust is the wafer, and the chocolate and hazelnut coating is the topsoil.
Eggs are closer. The center of the yolk being fully cooked. The outer half of the yolk uncooked but hot enough to be. The crust bursting when expansion escapes through a weakend crack solidifying as if continental crust.