For the Cake:

1. Preheat your oven to 350°F (175°C). Grease your cake pans and line them with parchment paper for easy removal.
2. In a medium bowl, whisk together the dry ingredients: flour, baking powder, baking soda, salt, cinnamon, nutmeg, and ginger. Set aside.
3. In a large bowl, whisk the sourdough discard, granulated sugar, brown sugar, eggs, oil, and vanilla extract until smooth and fully combined.
4. Gradually add the dry ingredients into the wet mixture, stirring until no streaks of flour remain. (Don’t overmix!)
5. Fold in the grated carrots, nuts, and raisins if using. The batter will be thick—it’s supposed to be.
6. Divide the batter evenly between the prepared pans. Smooth the tops with a spatula and bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean.
7. Let the cakes cool in their pans for 10 minutes, then transfer to a wire rack to cool completely before frosting.

For the Cream Cheese Frosting:

1. Beat the softened cream cheese and butter together until light and creamy.
2. Gradually add the powdered sugar, ½ cup at a time, until fully combined.
3. Mix in the vanilla extract and a pinch of salt. Beat on medium-high speed until the frosting is fluffy and smooth.

Assembling the Cake

1. If you’re working with two layers, place the first cake layer on a serving plate and spread a thick layer of frosting on top.
2. Gently add the second cake layer and frost the top and sides of the cake. Decorate with chopped nuts, if desired.
3. Slice and enjoy your masterpiece!