Sweet Potato Prep: Preheat the oven to 450°F. Set one large or two medium sweet potatoes on a baking sheet. Bake for at least one hour, until the potatoes are soft and tender. Cool the potatoes, then peel, mash, and measure for the recipe.
Once the potatoes are out of the oven, lower the oven temperature to 325°F.
Set out at 12 cup capacity Bundt pan. Generously grease the pan, making sure to coat every nook and cranny with butter or shortening. Then place a small amount of granulated sugar (or flour) in the Bundt pan and shake it around to coat evenly. You can use baking spray to grease and flour the pan at the same time, but be careful to coat it very thoroughly.
Set out an electric stand mixer. Cream the softened butter and brown sugar together until light and fluffy, about 3 minutes. Scrape the bowl with a spatula. Then beat in the eggs until well combined. Scrape the bowl again and beat in the cooled sweet potato mash.
Turn the mixer on low, and mix in the vanilla extract, ground cinnamon, baking powder, salt, and 3 cups of flour. Add the flour a little at a time until it is fully combined. Scrape the bowl one last time, and beat for another 10-20 seconds until the batter is smooth.
Scoop the cake batter into the prepared Bundt pan. Tap the pan on the counter to eliminate as many air bubbles as possible. Then smooth the top out evenly if needed.
Bake on the center rack for 65 to 75 minutes, until a toothpick inserted deep in the middle of the cake comes out clean.
Remove the cake from the oven and allow it to cool at least 20 minutes. Then gently flip the cake out onto a cooling rack and continue to cool to room temperature.
Cut and serve as is, or with whipped cream, or vanilla ice cream.
Notes
If you don’t have time to bake whole sweet potatoes, before baking the cake, you can find pure sweet potato puree in the baking aisle of some grocery stores.Wrap the cake thoroughly with plastic and keep it at room temperature for up to 4 days, or in the refrigerator for up to 10 days.