Stir 2 tbsp. cornstarch and 1/2 cup sugar together in a small saucepan. Stir in 1 egg thoroughly. Add 2 cups milk a little at a time, stirring after each addition. Add 2 tbsp. butter and cook over low heat, stirring constantly until thickened and bubbly. Add 1 tsp vanilla.
In a separate bowl (I mix mine together in my KitchenAid, against all popular instructions) mix the following dry ingredients together 2 cups flour, 1/2 cup sugar, 1-1/2 tsp baking powder, 2 tsp cinnamon, 1/2 tsp baking soda, 1/2 tsp salt, 1 cup nuts (optional).
To this bowl add your 1(ish) cup of bread starter , the pudding you made, 2 tbs canola oil or melted butter, and 2 eggs.
Pour batter into two well greased (with butter) and sugared bread pans. Bake at 325 degrees for 1 hour.