Lightly spoon the flour into a measuring cup, level off. . In a large bowl, stir together the flour, rolled oats, sugar, baking powder, baking soda, and salt. In another bowl, beat with a fork, the egg, oil, and vanilla extract until well blended. Add to the flour mixture. Add the Coca-Cola, prunes, and nuts, blend thoroughly with a spoon. Turn into a well-greased, lightly floured, 9 x 5 x 3-inch loaf pan. Garnish with prune halves, if desired. Bake in a preheated, 350 F oven for about 1 hour or until a wooden toothpick inserted in the centre comes out cleans. Cool on a rack for 20 minutes before removing the bread from the pan. Store in foil overnight before slicing.