Preheat oven to 350˚F. Spray or butter an 8-inch round baking pan with cooking spray or butter, and line the bottom with parchment paper.
In a large mixing bowl, combine apple sauce, oil, sugar, egg, and vanilla extract, and whisk together until smooth. Add cinnamon, cloves, ginger, baking soda, and salt, and whisk until combined.
Add flour and mix only until all the flour is incorporated. Fold in raisins and walnuts if using.
Using a spatula to get all the batter, transfer it to the prepared pan and bake for about 25 minutes or until a toothpick poked in the center comes out clean.
Allow the cake to cool completely if you’re icing it. If not, let it cool for 10 minutes before serving. Enjoy!
For the mascarpone icing:
Place all ingredients in the bowl of a standing mixer fitted with a whisk attachment or use an electric hand whisk and a large deep bowl. Beat the heavy cream, cold mascarpone cheese, sifted confectioner’s sugar, vanilla, and optional almond extract on high speed for about 5 minutes until thick and firm.
Make sure not to overbeat the cream or it can get grainy. If this happens, add very cold heavy cream in tiny amounts while letting the mixer run on low speed until the frosting becomes smooth.
Use the frosting immediately to ice the cooled-down apple cake or store it in an airtight container in the refrigerator for up to 1 week.