Experiment with additional eggs, egg powder.
In a glass bowl, combine the flour, sour dairy, and melted fat together. Cover with a clean dish towel or plate and allow this mixture to soak at least 8 hours, or even better, 24. ...You need warmth.
Once the batter has had a good soak, add in the rest of the ingredients. Fold in your add-ins at the end, if using.
Pour into greased muffin tins (preferably not aluminum or non-stick — stoneware is good). Bake in a 325 degree oven for about 30-35 minutes. A toothpick inserted into the center should come out clean
32 muffins.