Preheat your oven to 350 degrees F.
Prepare your cake pans by spraying them with baking spray and lining the bottoms with parchment paper.
Add the raisins to a small bowl, cover with boiling water, and let sit for about 10 minutes. Drain well.
In a medium bowl, combine flour, sugar, baking powder, baking soda, cinnamon, nutmeg, and salt. Whisk to combine.
In a large bowl, mix together eggs, vegetable oil, buttermilk, vinegar, and vanilla extract.
Add the dry ingredients to the wet ingredients and mix until just combined.
Gently fold in the shredded carrots, chopped walnuts, and raisins.
Divide the batter evenly between the prepared pans.
Bake for about 25 to 30 minutes, or until a toothpick comes out clean.
Let the cakes cool for about 20-30 minutes before inverting onto a cooling rack to cool completely.
Prepare the cream cheese frosting and frost the cooled cake layers.
Refrigerate the cake for at least 2 to 3 hours before serving.