Preheat your oven to 350°F. Grease a 9x5-inch loaf pan and line it with parchment paper, leaving some overhang on the sides for easy removal.
In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.
In a large mixing bowl, use an electric mixer to beat eggs, vegetable oil, orange juice and granulated sugar until well combined. Mix in the orange zest and vanilla extract until fully incorporated.
Pour the wet mixture into the flour mixture and whisk until incorporated. Do not overmix to keep the cake tender.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula. Bake in the preheated oven for 50–60 minutes, or until a toothpick inserted into the center comes out clean. If the top of the cake is browning too quickly, loosely cover it with aluminum foil during the last 15 minutes of baking.
While the cake is baking, prepare the glaze. In a small bowl, whisk together the powdered sugar and 3 tablespoons of orange juice until smooth. Add more orange juice if the glaze is too thick or more powdered sugar if it's too thin. Stir in the orange zest if desired for extra flavor.
Allow the cake to cool in the pan for about 15 minutes. Use the parchment paper overhang to lift the cake out of the pan and place it on a wire rack.
While the cake is still warm, drizzle the orange glaze over the top, letting it run down the sides.
Let the glazed cake cool completely before slicing. Slice and enjoy!