Preheat your oven to 350°F (175°C) and grease a round cake pan with butter or cooking spray.
In a large mixing bowl, combine the flour, sugar, baking powder, and salt. Mix well to ensure the dry ingredients are evenly incorporated.
In a separate bowl, whisk together the eggs, orange juice, orange zest, vegetable oil, and vanilla extract until well combined.
Slowly pour the wet ingredients into the dry ingredients, stirring gently until a smooth batter forms. Be careful not to overmix.
Pour the batter into the greased cake pan and smooth the top with a spatula.
Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove the cake from the oven and let it cool in the pan for 10 minutes. Then transfer it to a wire rack to cool completely.