Preheat the oven to 350°F (175°C). Grease and flour an 8-inch (20 cm) round cake pan or line it with parchment paper.
In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until well combined.
In a large bowl, beat the eggs and granulated sugar with an electric mixer on medium-high speed until pale and fluffy, about 3-4 minutes.
Reduce the mixer speed to low and slowly pour in the olive oil while continuing to mix until fully incorporated.
Add the whole milk, orange zest, orange juice, and vanilla extract to the wet ingredients and mix until combined.
Gradually add the dry ingredients to the wet ingredients, mixing on low speed just until combined. Do not overmix.
Pour the batter into the prepared cake pan and smooth the top with a spatula.
Bake for 38-42 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Remove the cake from the oven and let it cool in the pan for 10 minutes.
Turn the cake out onto a wire rack and allow it to cool completely before serving.