Preheat your oven to 350°F (175°C). Grease and line a 9x5-inch loaf pan.
In a medium bowl, whisk together the flour, baking powder, and salt.
In a large mixing bowl, cream the butter and sugar together until light and fluffy.
Add the eggs one at a time, beating well after each. Stir in the orange zest and vanilla.
Mix in the orange juice and milk, alternating with the dry ingredients until just combined.
Pour the batter into the prepared loaf pan and smooth the top.
Bake for 50–55 minutes, or until a toothpick inserted comes out clean.
Let the loaf cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
To make the glaze, whisk the powdered sugar with orange juice until smooth. Drizzle over cooled cake.