Preheat oven to 350°F (175°C) and grease a Bundt pan.
In a large bowl, mix flour, sugar, baking powder, cinnamon, nutmeg, and salt.
Add oil and eggs, and mix until well combined.
Fold in grated carrots and walnuts.
Pour the batter into the prepared Bundt pan.
Bake for 50 minutes or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.