Preheat oven to 350°F (175°C). Prepare a 9″ x 5″ loaf pan.
Combine flour, baking powder, baking soda, salt, sugar and spices.
In a separate bowl, whisk together brown sugar, eggs, vanilla and pumpkin puree. Gently fold into flour mixture using a rubber spatula. Transfer batter to prepared loaf pan and smooth top.
Bake for 45-55 minutes, until top springs back when gently pressed or tester comes out mostly dry, with just a few moist crumbs. Cool 5 minutes in pan before transferring to a wire rack to cool.
Meanwhile, whish together sour cream and icing sugar to make the glaze. Drizzle over loaf when it is only slightly warm. Sprinkle with chopped candided ginger or pecans if desired.