Preheat your oven to 350°F (175°C) and grease a baking dish.

In a large mixing bowl, combine the mashed sweet potatoes, sugar, milk, melted butter, eggs, and vanilla extract until smooth.

In a separate bowl, whisk together the flour, baking powder, cinnamon, nutmeg, and salt.

Fold the dry ingredients into the wet mixture until just combined.

Pour the mixture into the greased baking dish and spread it evenly.

Bake for 45-50 minutes until the top is golden and a toothpick comes out clean.

Let cool for 10-15 minutes before slicing and serving warm.