Preheat the oven to 325°F (170°C). Spray a Bundt pan or two 9" round cake pans with nonstick spray.

In a large bowl, stir together the flours, sugar, baking soda, cinnamon and salt. In a smaller bowl, stir together the oil, eggs, and vanilla. Add the oil mixture, grated sweet potatoes and applesauce to the dry ingredients and stir by hand until almost combined. Add the nuts and dried fruit and stir just until the batter is blended.

Pour the batter into the prepared pan(s). Bake for 1 hour and 15 minutes for a Bundt cake, or 40-45 minutes for layer cakes, until the tops are cracked and springy to the touch and the edges are pulling away from the sides of the pan. Cool the cake(s) in the pan for 10-15 minutes, then loosen the edge with a knife, and invert onto a wire rack to cool completely.

To make the frosting, beat the cream cheese and butter with an electric mixer until smooth; add the lemon juice and 2 cups of the icing sugar and beat until well blended.

Add the remaining icing sugar, a bit at a time, until you have a soft, spreadable consistency.