Why is my pound cake deflating

[philjack56]

Have made is pound cake many times in the past, successfully. I recently started to make it again and it keeps deflating after I take it out the oven. I'm baking it from memory, maybe I'm missing something. Help.

21/4 cups four (it was originally given to me using all purpose flour with baking powder. I started using self-rising with success)
1 package vanilla instant pudding
5 eggs
t spoon vanilla
1 1/2 cups sugar
1 stick of butter
1/2 cup oil
1 8oz sour cream
It used to come up so perfect, what am I doing wrong now.

Help

 

[Mona]

It sounds like your pound cake might be deflating due to a few potential reasons: check that your oven temperature is accurate, avoid overbeating the batter (especially after adding eggs), and be mindful that self-rising flour already has baking powder, so adding extra could cause the cake to over-rise and collapse. Also, let the cake cool gradually to prevent it from deflating too quickly, and ensure you're using the same brand of sour cream and pudding mix as before for consistent results. Hopefully, one of these tips helps get your cake back to perfection!