Preheat oven to 350°
Grease 9x5x3 pan (I use Crisco All Vegetable Shortening to grease my pans)
Mix flour, baking soda, salt, and sugar in a medium sized mixing bowl
In a small bowl, beat egg
Put the 3 Tbs vinegar in a measuring cup and add enough water to make the liquid mixture a total of ⅔ cup.
Add vinegar water to bowl with egg and stir
Add grated orange peel and butter to bowl with liquids and beat to mix (butter will not dissolve completely but should be broken into smaller bits)
Add liquid mixture to flour mixture
Stir until moist
Fold in cranberries and optional pecans
Turn into greased loaf pan
Bake 60 minutes until top is golden brown and toothpick in middle comes out clean
Cool 10 minutes on a cooling rack
Serve with butter or cranberry sauce
Store leftovers at room temperature in an airtight bag or container