- Preheat your oven to 350°F. 
- Grease a 9-inch round cake pan, and line the bottom with parchment paper. 
- In a bowl, mix together the baking powder, salt, and flour, ensuring they are well combined. 
- In another bowl, beat the sugar and eggs until fluffy. 
- Add the orange zest and orange olive oil, continuing to mix until combined. 
- Gradually add the flour mixture and milk, alternating between the two. 
- Beat until the batter is smooth. 
- Pour the batter into the prepared cake pan and smooth the top. 
- Bake for about 30-35 minutes until golden and a toothpick comes out clean when inserted.