1-First Step: Prepare the pan and oven Start by preheating your oven to 180°C (350°F) if you are using a conventional oven. If you are baking in a convection oven, set it to 160°C (320°F) because the fan helps the cake bake faster. Grease a 9-inch springform cake tin and line the bottom with parchment paper. This size matters because a smaller pan can cause the cake to sink or overflow.

2-Second Step: Zest and blend the orange Zest the entire orange into a large bowl, but only take the top orange layer. Avoid the white pith, since it can make the cake bitter. Next, cut the orange in half, remove any seeds, and blend the flesh until smooth. The blended orange flesh should weigh about 120 g, though a small difference is fine. Set it aside while you mix the rest of the batter.

3-Third Step: Mix the dry ingredients Sift together the flour, cornstarch, baking powder, and salt in a separate bowl. Sifting helps break up lumps and makes the batter easier to fold later. This step also helps the cake bake more evenly. Keep this mixture nearby so you can add it at the right time without rushing.

4-Fourth Step: Cream the fats, sugar, and zest Add the butter, oil, and sugar to the bowl with the orange zest. Use a mixer on medium speed for about 2 minutes, until the mixture looks light and fluffy. The zest mixes into the sugar and fat, which helps release even more orange flavor. This is one of the key moments that gives this whole orange cake super moist recipe its bright taste.

5-Fifth Step: Add the eggs one by one Crack in the eggs one at a time and mix on low speed. Let each egg blend in fully before adding the next one. This slow approach helps the batter stay smooth and keeps the texture steady. If the mixture looks a little thicker at this point, that is perfectly fine.

6-Sixth Step: Add the orange, milk, and vanilla Pour in the blended orange, milk, and vanilla extract or essence. Mix on low speed until everything comes together. The batter may look curdled, but that is normal when citrus meets fat. Do not worry if it looks a little rough at first, because it smooths out once the dry ingredients go in.

7-Seventh Step: Fold in the dry ingredients Add the sifted dry mixture to the bowl and fold it in gently with a spatula. Stop mixing as soon as the flour disappears. Over-mixing can make the cake dense, so use slow, careful strokes. The batter should look thick, smooth, and ready to bake.

8-Eighth Step: Transfer to the pan and bake Pour the batter into the prepared pan and smooth the top. Tap the pan once on the counter to release air bubbles. Bake for about 35 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs. Avoid opening the oven door before the center has started to set, since that can cause sinking.

9-Ninth Step: Cool and finish Once baked, let the cake cool in the pan for 15 minutes. Run a knife around the edges, remove the springform ring, and let it cool to room temperature. Before serving, dust the top with powdered sugar. That is really all it needs, since the flavor is already bright and satisfying on its own.