Preheat the oven to 350°F (175°C). Grease and flour a loaf pan.

In a mixing bowl, whisk together the flour, baking powder, baking soda, and salt.

In another bowl, cream the softened butter and sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the buttermilk, lemon zest, orange zest, and vanilla extract.

Gradually add the dry ingredients to the wet ingredients, mixing 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 in the center comes out clean.

Let the loaf cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

In a small bowl, whisk together the powdered sugar, lemon juice, and orange juice until smooth.

Drizzle the glaze over the cooled loaf before serving.