1. Preheat your oven to 175°C. Grease and flour a 22cm x 12cm loaf pan, or line it with parchment paper.
2. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
3. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy. You can use an electric mixer or beat by hand using a wooden spoon.
4. Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.
5. Gradually add the dry ingredient mixture to the butter mixture, alternating with the buttermilk. Begin and end with the dry ingredients, mixing just until combined.
6. Add the blood orange zest and juice to the batter, stirring until evenly incorporated.
7. Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
8. Bake in the preheated oven for 45-55 minutes or until a toothpick inserted into the centre comes out clean.
9. While the cake is baking, prepare the glaze. In a small bowl, whisk together the powdered sugar and blood orange juice until smooth and well combined.
10. Once the cake is done, remove it from the oven and let it cool in the pan for about 10 minutes. Then, transfer the cake to a wire rack placed over a baking sheet.
11. Drizzle the glaze over the warm cake, allowing it to soak in. Let the cake cool completely before slicing and serving.