Thoroughly mix flour, cream of tartar, soda and salt. Then cut the butter / lard mixture into these dry ingredients. Add the remaining ingredients and mix well.
Filling:
2 eggs
1 cup brown sugar
1 cup flour
1/2 tsp vanilla
1/2 tsp salt
Roll first mixture and spread filling over all.
Roll up like a jelly roll and slice; about 1 inch thick.