Preheat oven to 350 degrees F. Generously butter and flour a 9-inch bundt pan and set aside.

Combine the flour, baking powder, and salt in a medium bowl. Whisk to blend and set aside. 

In the bowl of a stand mixer, combine the sugar and blood orange zest. Rub the mixture with your hands for a minute or two to incorporate the zest into the sugar. Add the eggs, and fit the stand mixer with the whisk attachment. Beat on medium speed for 2-3 minutes, until the mixture is thick and creamy. Add the dry ingredients and mix on low speed, just until incorporated. 

Pour batter into the prepared pan, and bake for 45-60 minutes, until a toothpick inserted into the center comes out clean. Let cake cool completely in the pan before inverting onto a platter or plate. 

To make the syrup, combine the juice and sugar in a small saucepan. Bring to a boil, then reduce heat and allow to simmer for 1-2 minutes. Prick the cooled and inverted cake with a fork, then pour the syrup over the cake with a small spoon. 

To make the glaze, combine powdered sugar and juice, beginning with just 1 tbsp. of juice and adding more as needed until the glaze is just thin enough to pour. Drizzle glaze generously over the cake, and sprinkle with zest if desired. Allow to cake to set, then serve at room temperature.