Preheat your oven to 350°F (175°C) and grease a baking dish.
In a large bowl, combine the mashed sweet potatoes and sugar.
Add eggs, milk, melted butter, and vanilla extract to the mixture; stir until well blended.
In another bowl, mix cornmeal, flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Pour the batter into the prepared baking dish.
Smooth the top with a spatula for even baking.
Bake in the preheated oven for 30-35 minutes or until golden brown.
Check doneness by inserting a toothpick; it should come out clean.
Allow cooling for 10 minutes before slicing and serving.