Preheat oven to 350F. Line a 9-inch cake pan with parchment paper.

In a bowl, combine ground chicken, hot dogs, and egg. Transfer to the prepared pan and spread with fingers.

Bake in preheated oven for about 40 minutes, or until the meat is cooked through.

While the cake is cooking, boil the diced sweet potatoes until fork tender, about 20 minutes. Strain and beat with an electric mixer until mostly smooth.

Cool the cake completely before spreading the mashed sweet potatoes on top and serving.