1. Preheat the oven to 350°F and grease a 9×13-inch baking pan. Line with parchment paper if desired.

2. In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, and cloves.

3. In a large bowl, whisk the brown sugar, granulated sugar, and vegetable oil until smooth.

4. Add the eggs one at a time, whisking well after each addition.

5. Stir in the applesauce, buttermilk, and vanilla extract until combined.

6. Add the dry ingredients to the wet ingredients and fold gently until no dry streaks remain. Do not overmix.

7. Pour the batter into the prepared pan and smooth the top.

8. Bake for 32 to 38 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.

9. Let the cake cool completely in the pan before frosting.

10. Beat the softened cream cheese and butter until smooth and creamy.

11. Add the powdered sugar gradually, then mix in the vanilla extract and salt until fluffy.

12. Spread the frosting over the cooled cake and top with chopped nuts if using. Slice and serve.