Set the oven at 350 degrees.Oil the bundt pan and dust lightly with flour.
Place pecans on a baking sheet, and toast for 10 minutes. Cool completely, and chop roughly.Cover raisins with boiling water, and let soak for 25 minutes.
Drain and set aside.In a bowl, whisk together pumpkin, oil, syrup, soymilk, vinegar, and vanilla.In a large bowl, use a clean whisk to mix date sugar, flour, baking soda, baking powder, spices, and salt.Using a rubber spatula, fold the pumpkin mixture into the dry ingredients.When the dry ingredients are halfway incorporated, add the raisins and the chopped pecans.Continue folding just until the mixture comes together; do not overmix.
Pour batter into prepared pan.Smooth the top with a rubber spatula.
Bake for 45 minutes, rotating the cake from front to back after 20 minutes, or until a toothpick inserted into the center comes out clean.Cool in the pan for 15 minutes.Invert the cake onto a wire rack, and continue cooling.
Transfer to a plate, and dust with powdered sugar.