Preheat the oven to 350°F (175°C) and line a muffin tin with cupcake liners.

In a mixing bowl, whisk together the dry ingredients: flour, baking powder, baking soda, cinnamon, nutmeg, and salt.

In another bowl, combine the wet ingredients: oil, sugar, eggs, and vanilla extract. Mix until well combined.

Gradually add the dry mixture to the wet mixture, stirring until just combined. Fold in the grated carrots and crushed pineapple.

Spoon the batter into the prepared muffin tin, filling each liner about 2/3 full.

Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out clean.

Allow the cupcakes to cool in the tin for 10 minutes before transferring to a wire rack to cool completely.

In a mixing bowl, beat together the softened cream cheese and butter until smooth.

Gradually add the powdered sugar and vanilla extract, mixing until creamy and well combined.

Once the cupcakes are completely cooled, frost them with the cream cheese frosting using a spatula or piping bag.

Optionally, garnish with chopped walnuts or a sprinkle of cinnamon.