There's a well-known Midrash on Genesis 24:67, that discusses the legacy of Sarah which was carried on by Rivka, namely a sheltering cloud over her tent (i.e. hospitality or transparency), a flame burned from one Shabbat to the next and there was blessing in her dough.
What was the blessing in her dough? Rav Pinchas of Koretz offers a novel interpretation. Sarah's husband, Avraham, was a man of means, he explains. Eking out more dough was not a real concern in their household. They could afford all the flour they needed. Therefore the blessing was not about quantity.
Rav Pinchas argues that the blessing must have referred to the qualitative characteristics of her loaves — the taste, texture, smell and appearance. He therefore writes that women should make baking a happy experience, so that the challah dough is pleasing and blessed, like those of Sarah Imeinu.