Prune Cake ( Grandma)

2 1/4 cups of flour
1/2 cup of sugar and 1 egg or 1+3 flax +water
1/2 tea spoon of baking soda and table spoon of vinegar
8 1/2 table spoons of oil
Filling: any favorite jam, but as per grandma - "it is the best with prune butter"

Rub flour and oil by hand to incorporate oil. Gradually add sugar,  egg, baking soda and vinegar mix using dough cutter till mix forms a ball. Divide into 8 pieces, form into balls and put into freezer for about 2 hours.
Grade half of the dough, place filling, grade the other half f the dough on the top.
Bake at 350 F (175C) for about 30 minutes or till pale golden.

Let cool, sprinkle with powdered sugar.