I have been making this recipe sense the 1970's. I was given the recipe when I lived in Utah. Everyone loves it. It is similar to your Muffin recipe Nancy.
Pat So. Calif.

Long Time Muffins

2 cups boiling water
5 teaspoons baking soda
1 cup shortening
2 cups sugar
4 eggs
4 cups All-Bran cereal
2 Cups 40% Bran Flakes cereal
1 quart buttermilk
5 cups flour

Add soda to boiling water, set aside and let cool. Cream shortening and sugar; add eggs and mix well. Add the rest of the ingredients and mix together. Add cooled water and soda mixture; mix until blended. Keep covered in the refrigerator for as long as two weeks. Cook fresh muffins as desired.

TO BAKE: Preheat oven to 350 degrees. Fill muffin cups tins with paper muffin cups inserted, 3/4 full. Bake for 20 minutes.

NOTE: May add: chocolate chips, nuts or blueberries when ready to bake.

* Powdered buttermilk does not have to be mixed separately. I just add the powder with my flour and the water with the my other liquids and let it mix in the batter.
Nancy Rogers

http://www.nancyskitchen.com