Preheat the oven to 350°F (180°C), and coat a 9-inch (23-cm) cake pan with oil or butter. Line the bottom of the pan with parchment paper.
In a large bowl, whisk together the orange zest and granulated sugar. Whisk in the flour, poppy seeds, salt, baking powder, and baking soda.
In a separate large bowl, combine the olive oil, milk, orange juice, and eggs. Don’t worry if the mixture separates slightly.
Make a well in the center of the dry ingredients then pour in the wet ingredients. Whisk together just until everything is well incorporated, scraping down the sides of the bowl as necessary.
Pour the batter into the prepared cake pan, bake until the top turns golden and a toothpick inserted in the center comes out clean or with a few damp crumbs, 60 to 70 minutes. Let the cake cool completely.
To loosen the cake, run a knife around the edges. Gently remove the cake from the pan, peel off the parchment, then place on a serving plate.