Preheat the oven to 350°F. Lightly grease an 8 1/2" x 4 1/2" loaf pan., In a medium-sized bowl, beat together the brown sugar, boiled cider or other liquid, vegetable oil, eggs, and vanilla until smooth., Whisk the baking powder, baking soda, salt, and cinnamon into the flour, then add the dry ingredients to the liquid ingredients in the bowl, stirring or beating gently until smooth., Stir in the zucchini, walnuts, and raisins or currants., Scoop the batter into the prepared pan, smoothing it if necessary. Sprinkle with brown sugar., Bake the bread for 55 to 65 minutes, until a toothpick inserted into the center comes out clean. The top (just under the crust) may seem a bit sticky; but so long as the toothpick doesn't reveal wet batter, it's done., Remove the bread from the oven, and cool it in the pan for 10 minutes. Turn it out of the pan onto a rack to cool completely. For best results, don't slice until it's cool., Store the bread at cool room temperature, well wrapped, for several days; freeze for longer storage.