You can stamp vent holes and rising steam on top of the pie, or add a smiley face for a cheerful touch.
Coordinating set ideas: Stamp this pie inside the oven from Sprinkled with Joy for a cute baking scene. Find lots of different smiley face options (and some apples to make this an apple pie) with Thanks a Bushel. Add a "be sweet" sentiment with Scripty Be and Scripty Sweet.
Approximate stamp sizes: [pie] 1" x 2/3" [large sentiment] 2 2/5" x 1/2"