Dessert with a shell

PIE

This sweet treat often has a flaky crust and is sliced into wedges.

The clue "Dessert with a shell" plays on the double meaning of "shell." While a shell can refer to the hard outer covering of nuts or sea creatures, it also hints at the crust of a pie, which acts like a shell for the filling. "Pie" fits perfectly as a dessert known for its crusty outer layer. The wordplay cleverly connects the idea of a shell to a common baked treat.