Русско-английский кулинарный словарь

What is Softasilk® Cake Flour?
Softasilk is specially formulated for cake baking. It is milled from select soft wheat that gives cakes high volume, fine crumb and delicate, tender texture.
Is it necessary to sift Softasilk® Cake Flour?
Softasilk is sifted many times during the milling process, so it is not necessary to sift before using. Simply spoon lightly into a measuring cup and level off.
Can Softasilk® Cake Flour be substituted for all-purpose flour?
Yes. Use 1 cup plus 2 tablespoons of Softasilk for every cup of all-purpose flour.

просто мука очень мелкого помола. Это название продукта от Филсберри, они делают много всяких вещей для выпечки.