Spray the bottom of two 9-inch glass loaf pans. Preheat oven to 325 degrees F. Combine flour, salt, baking soda, and spices in a bowl. Measure sugar, oil, and molasses in a separate mixing bowl. Add eggs and mix until smooth.
Add flour mixture to molasses mixture alternating with the buttermilk. Mix until smooth. Stir in raisins or cranberries if desired.
Pour into the prepared pans and bake for 55 minutes. Try not to open oven door during baking, as it may cause center to fall. A toothpick inserted in center should come out clean when it’s done.