Butter and flour a 23-cm (9-inch) Bundt pan. The bottom of the pan can have engraved patterns.
In a bowl, combine the flour, baking powder, baking soda, cinnamon, and nutmeg. Set aside.
In another bowl, combine the pineapple, dates, raisins, and pecans. Set aside.
In a large bowl, beat the vegetable oil and brown sugar with an electric mixer until smooth. Add the eggs, one at a time, beating thoroughly between each addition, until smooth and creamy. Add the grated beets. Add the dry ingredients to the liquid ingredients. Finish by incorporating the fruit and nut mixture.
Pour the batter into the pan. Bake for about 1 hour or until a toothpick inserted in the cake comes out clean. Let rest for 10 minutes before unmoulding from the pan on a wire rack. Let cool completely.