Recipe(tried): How to prevent a fallen angel food cake

If the cake was underbaked - and it sounds like yours was - it's the probable reason it fell. Check your oven for temperature accuracy. Place a good oven thermometer inside for 20-30 minutes to make sure the oven reaches the temperature you've set it at. If it isn't, it will need to be recalibrated. If it is accurate, you probably just failed to leave it in long enough. "Almost golden" is another clue the cake wasn't done; angel cake should be dark golden when it's done. The oven door shouldn't be opened for any reason during baking, either; but that'll usually cause the cake to fall during baking rather than after removal from the oven.

Probably the second most common cause of fallen angel food cake is failure to immediately turn the cake upside down to cool in the pan after removing it from the oven. Did you do that?