Ok ,so I have a recipe that calls for 2 3/4 cake flour but all I have is 2 cups. And 2 1/2 tsp baking powder, can I use ap flour for the remaining 3/4 cup and adjust baking powder or should I put on my big girl pants & go to the store?

If I were you I would use 3/4 cup AP flour. I doubt it will make any difference whatsoever. You could sub out 1 tbsp of AP for 1 tbsp of corn flour

All cake flour basically is is AP + corn flour (it's to do with protein levels). Honestly though, I wouldn't worry.

Thanks so much. Going to try it out now. Fingers crossed......

As LisaPeps said, you can use the AP flour.

1 cup sifted cake flour can be replaced with 1 cup sifted all purpose flour minus 2 Tbsp.

You will need 73 - 74 grams of ap flour to replace 3/4 cup sifted cake flour.

Or you will need 82 grams of ap flour to replace 3/4 cup cake flour.

HTH