Put an oven rack on the lower-middle position of the oven and preheat to 350 degrees F. Spray the sides of a 9-inch round nonstick cake pan with cooking spray.
For the Spiced Sour Cream: In a medium bowl, mix together the sour cream, sugar, vanilla, cinnamon and ginger. Cover and refrigerate until serving.
For the Cake: Put the orange juice and cranberries into a small bowl and let soak for 20 to 30 minutes.
Pour the maple syrup evenly into the prepared pan. Sprinkle evenly with 1/4 of the cranberry mixture and 1/4 of the pecans. Shred enough of the sweet potato to make 1 cup and set aside. Slice the remaining sweet potato into 1/8-inch thick slices and lay the slices in a decorative pattern on top of syrup mixture. Sprinkle evenly with the remaining cranberry mixture and pecans. Set aside.
In a medium bowl, whisk together the eggs, milk, and vanilla and orange extracts until evenly combined. Set aside.
In the bowl of a standing mixer, add the flour, sugar, baking powder, cinnamon, nutmeg, ginger and salt. Using the paddle attachment, blend the mixture on the lowest speed for 1 to 2 minutes. With the mixer still on the lowest speed, add the butter, 1 piece at a time, until the butter and flour are blended into pea-sized pieces, about 3 to 4 minutes.
Add 1/2 cup of the egg mixture to the flour and mix on the lowest speed until blended about 15 to 20 seconds. Increase speed by 1 setting and beat for about 30 seconds. With the mixer still running, add the remaining egg mixture in a slow, steady stream and beat for about 30 seconds. Stop the mixer and scrape the sides and bottom of the bowl with a rubber spatula. Beat again for 15 to 20 seconds until thoroughly blended. Remove the paddle, scraping down the bowl, as necessary. Gently stir in the reserved shredded sweet potato.
Pour the batter over the mixture in the pan and smooth lightly with a rubber spatula. Bake for 25 minutes then lower the oven temperature to 325 degrees F. Bake until a toothpick or wooden skewer inserted in the center comes out clean. Remove from oven to a wire rack for 15 to 20 minutes. Invert onto a serving plate and serve warm or at room temperature. Garnish with dollops of spiced sour cream and mint sprigs, if desired.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.