Preheat your oven to 350 degrees F and spray a 12-count mini bundt pan OR 10-inch bundt pan with non-stick cooking spray.
In the bowl of an electric mixer, add cake mix, dry vanilla pudding mix, eggs, milk, vegetable oil, and pumpkin pie spice.
Mix at low speed until just combined, about 30 seconds, and then mix on medium speed for 2 minutes.
If you do mini bundts, you'll have to do these in 2 different batches. Fill each tin 3/4 full and bake for 15-20 minutes, let cool, remove from the tin, spray with non-stick spray, and cook your second batch.
If making a large bundt cake, fill the pan and bake for 35 minutes. Let cook for 10 minutes and remove the cake from the pan.
Let cakes cool and dust with powdered sugar.