Which cake ingredients act as tenderizes and interfere with gluten formation ?

There is a lot of information, but it's spread around and you have to spend some time searching. After you find it, the bottom line is "Follow the recipe exactly!"

First, there are three to twenty kinds of flower, depending on who grades them, but all you care about is cake flour, bread flour, and all purpose flour. Cake flour is high in starch and low in protein. Bread flour is high in protein and low in starch. AP flour is somewhere between, usually a mix of two kinds.

Gluten = protein. So use cake flower and you will get a nice cake. Use AP flour and it will be an ok cake. Use bread flour and you get, um, bread.

Another thing you learn is that if you stir the flour and spoon it into a measuring cup, then level it by dragging the handle of the spoon across the top, you reliably get between 4.20 and 4.25 ounces per cup. If you use the cup to scoop the flour and then level by scraping it on the bag, you can get up to 6.5 ounces per cup.