Preheat your oven to 400°F (200°C) and line a 12-cup muffin tin with paper liners.

In a large mixing bowl, whisk together all-purpose flour, granulated sugar, baking powder, and salt until well combined.

Add the zest of 2 large oranges to the dry mixture and rub it into the flour with your fingertips.

In a separate bowl, whisk together the egg, milk, vegetable oil, and juice of 1 large orange until well combined.

Pour the wet mixture into the bowl of dry ingredients and gently stir until just combined, being careful not to overmix.

Divide the batter evenly among the prepared muffin cups, filling each to about two-thirds full.

Bake for 18 to 22 minutes, or until the tops are golden brown and a toothpick inserted comes out clean.

Let muffins cool in the pan for 5 minutes before transferring to a wire rack. Prepare the glaze by mixing powdered sugar with orange juice.

Drizzle the glaze over the muffins for a delightful finishing touch.