Which dessert item is mentioned to contain gelatin?

Buttermilk panna cotta is the dessert that contains gelatin. Gelatin is a key ingredient in panna cotta, which is a creamy dessert that achieves its smooth, gel-like consistency thanks to the gelatin's ability to set when mixed with the cream and buttermilk mixture. The use of gelatin allows the panna cotta to hold its shape once cooled, creating a delicate and silky texture that is characteristic of this Italian dessert.

In contrast, while other desserts can have various textures and components, they do not necessarily rely on gelatin. For example, brown sugar caramel cream may utilize sugar and cream to create a rich and decadent flavor without the need for gelatin, and chocolate mousse employs whipped cream and eggs to achieve its light, airy consistency. A fruit tart typically consists of a pastry crust filled with custard and topped with fresh fruits, again without the use of gelatin. This distinctive role of gelatin in panna cotta makes it the correct choice.