Center a rack in the oven and preheat the oven to 350 degrees F. Butter an 8 1/2 x 4 1/2-inch loaf pan, dust the inside with flour and tap out the excess. Put the pan on an insulated baking sheet or on two regular baking sheets stacked one on top of the other. (This extra insulation will keep the bottom of the bread from over-baking).
Begin by dicing the mangoes. Set aside.
Whisk the eggs and oil together.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, spices and salt. Rub the brown sugar between your palms into the bowl, breaking up any lumps, then stir it in.
Pour the wet ingredients over the dry, switch to a sturdy rubber spatula or wooden spoon and mix until blended---the batter will be very thick (really more like a dough than a batter) and not easily mixed, but persevere, it will soon come together.
Stir in the mango, raisins and zest. Scrape the batter into the pan and smooth the top with a rubber spatula.
Bake the bread for 1 1/2 hours, or until it is golden brown and a thin knife inserted into the center comes out clean. (If the bread looks as if it’s getting too brown as it bakes, cover it loosely with a foil tent). Transfer the pan to a rack and cool 5 minutes before running a knife around the sides of the pan and unmolding. Invert and cool to room temperature right side up on the rack.
Serving: As good as this bread is freshly baked, I think it's even better the next day. one day spent wrapped in plastic seems to intensify the fruit and spice flavors. Of course, if you can't wait, don't. Just cut the loaf into thick slices and serve with tea, hot or iced, or coffee.
Storing: Wrapped in plastic, the cake will keep for about 4 days at room temperature.
Recipe from Baking: From My Home to Yours by Dorie Greenspan