Preheat the oven to 350° F. Line a (9×5 inch) loaf pan with parchment.In a bowl, combine the almond flour, baking powder, baking soda, and salt. Add the honey/maple, yogurt, eggs, grapefruit zest, vanilla, and melted coconut oil. Mix well until thoroughly combined, and no lumps remain. Pour the batter into the prepared pan. Bake for 50-60 minutes, or until the center is just set. If the cake is browning cover with tin foil to finish baking. Let cool completely before frosting.Meanwhile, make the glaze. In a bowl, whisk together the powdered sugar and grapefruit juice. Stir in the zest and ginger. Pour the glaze over the cooled loaf. Let set for 1 hour (or so), slice, and eat