Preheat Oven and Prepare the Pan
Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan or springform pan, and line the bottom with parchment paper for easy release.
Combine Dry Ingredients
In a medium bowl, whisk together the flour, sugar, baking powder, baking soda, and salt. Set aside.
Mix Wet Ingredients
In a large mixing bowl, whisk together the olive oil, milk, eggs, citrus zest, citrus juice, and vanilla extract until smooth and well combined.
Combine Wet and Dry Ingredients
Gradually add the dry ingredients to the wet mixture, stirring gently with a spatula until just combined. Avoid over-mixing to keep the cake light and fluffy.
Bake the Cake
Pour the batter into the prepared cake pan and smooth the top. Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean and the top is golden.
Cool and Serve
Allow the cake to cool in the pan for 10 minutes, then transfer it to a cooling rack to cool completely. Dust with powdered sugar before serving, and garnish with fresh berries or whipped cream if desired.