Low-fat double blueberry marfin

A pile of frozen blueberries that broke their skin in the freezer, spilled oar juice and was frozen. So the surface was covered with purple little ice. The colour of frozen blueberries is not blue purple, as fresh blueberries are, but a deep purple red. Make cake with it, but I've made some cake with fresh blueberries. Suddenly I thought I'd never get a chance to use blueberry jam. Blueberry's last life, let them gather in the same cake. A fast-hand blueberry marfin first. Blueberry jam is used as a direct substitute for equivalent white sugar. Sweet sour jam may not bring the same sweetness to the cake body, but it will add color. I don't want the cake to be too dark, but the jam is just sugar, and I don't mind the sweet ones anyway. Refrigerated blueberries produce fruit grains, blue purple and red purple mixed with silk in the paste. Nor do you have to mix these twigs into the paste, so that they exist. However, in the process of modelling and baking, these dark scratches seem to have disappeared. Double blueberry marfin, not so sweet, but looks pretty good。