Preheat the oven to 350°F.

Butter and flour the Bundt pan.

Sift the dry ingredients into a medium bowl and set aside.

In a stand mixer fitted with the paddle attachment, beat the eggs and brown sugar on medium-high speed for about 3 minutes, or until thick.

Add the vegetable oil and applesauce. Mix on medium speed for about 30 seconds, or until combined.

Add the mashed sweet potato and vanilla extract, and mix until smooth.

Gradually add the flour mixture to the wet ingredients and mix on low speed just until combined. Fold in the walnuts.

Pour the batter into the prepared Bundt pan. Bake for 45 minutes, checking with a toothpick at the 35-minute mark.

Remove the cake from the oven and let it cool in the pan for 10 minutes. Then carefully turn it out onto a wire rack to cool completely.

While the cake cools, beat the cream cheese, sugar, and vanilla extract together until smooth.

Add the half-and-half and stir until fully combined.

Pour the cream cheese frosting over the cooled cake and sprinkle with a little cinnamon, if desired. Slice and enjoy!