Preheat your oven to 350°F (175°C). Grease and flour a 9×13 inch baking pan to prevent sticking.

In a bowl, whisk together the flour, baking powder, baking soda, cinnamon, and salt until well combined.

In a large bowl, beat together the sugar, eggs, vegetable oil, and vanilla extract until the mixture is smooth and creamy, about 2-3 minutes.

Gradually add the dry ingredients to the wet mixture, stirring just until combined. Avoid overmixing to keep the cake light and airy.

Fold in the grated carrots, crushed pineapple, and walnuts (if using).

Pour the batter into the prepared baking pan and spread it evenly.

Bake for 35-40 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out clean.

Let the cake cool completely in the pan on a wire rack.

For the frosting, beat the softened cream cheese and unsalted butter together until creamy and smooth.

Gradually add the powdered sugar and vanilla extract, mixing until it reaches a fluffy, spreadable consistency.

Spread the frosting generously over the cooled cake and garnish with pineapple chunks and shredded carrots for an appealing presentation.