Peel and chop about two medium sweet potatoes into large pieces. Boil them in a pot of water for 15–20 minutes, or until tender enough to easily pierce with a fork. Once cooked, drain the water and let the sweet potatoes cool before mashing them.

Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans with butter or baking spray.

In a large mixing bowl, whisk together the dry ingredients: flour, baking powder, baking soda, cinnamon, nutmeg, and salt.

In a separate large bowl, mix together the granulated sugar, brown sugar, and vegetable oil. Incorporate the eggs, one at a time, and then stir in the cooled, mashed sweet potatoes and vanilla extract.

Gradually add the dry mixture to the wet ingredients, stirring gently until just combined.

Pour the batter evenly into the prepared cake pans and bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool for about 10 minutes before transferring to wire racks.

Beat together the softened cream cheese and unsalted butter until smooth. Gradually add powdered sugar and mix until fluffy, adding milk to achieve the desired consistency.

Once the cake layers are completely cool, frost the first layer generously, then place the second layer on top and frost the top and sides. Optionally garnish with toasted pecans.