In a bowl add your whole box of angel food cake mix and water (if it has a separate egg white packet, add that too). I use a rubber spatula to whip it up for about 2 minutes until it is nice and fluffy and has puffed up in the bowl - you don't want to overmix it, once it becomes light and frothy, stop stirring.
Sprinkle in your pumpkin pie spice.
Add half your can of pumpkin puree and use a spatula to fold in until well combined, then add remaining half and do the same thing. Like I said, only stir enough to combine, then stop.
Once combined use spatula to "cut" thru the batter a few times to release any air bubbles that are trapped.
Very lightly spray non stick spray inside your bundt pan and pour mixture in.
Bake for 40 minutes or until middle of bundt cake springs back when touched gently, get it right when it starts to spring back so it maintains it's moisture and comes out really moist but all the way cooked thru.
Cool completely in pan, then gently flip over on to a cake plate and it should slide out. Cut with serrated knife and serve. Can squeeze some cream cheese frosting on the top!