There is no one definitive answer to this question, as there are many different ways to make gingerbread. However, one popular recipe for Mendenhall sourdough gingerbread comes from the book "The New Art of Cookery, According to the Present Practice" by Hannah Glasse. This recipe calls for flour, sugar, butter, eggs, ginger, nutmeg, and lemon juice.
Cream brown sugar and shortening and beat.
Then add molasses and egg,beating continuously.
Sift dry ingredients together and blend into hotwater.
Then beat this mixture into creamed mixture.
As the last step, addthe sourdough starter slowly, mixing carefully to maintain a bubbly batter.
Bake in pan at 375 degrees F for about 30 minutes or until done.
Servewith ice cream or whipped cream while still hot if possible.