1-Preheat and prep pans: Preheat oven to 350°F (175°C), grease two 8-inch round pans and line bottoms with parchment paper.

2-Mix dry ingredients: Sift together flour, cornstarch, baking powder, and salt; set aside.

3-Cream butter mixture: Beat butter, oil, sugar, and lemon zest on medium speed for 2–3 minutes until light and fluffy.

4-Add eggs: Add eggs one at a time, beating well after each addition until smooth and creamy.

5-Add wet ingredients: Mix in milk, yogurt, and lemon juice on low until combined (batter may look slightly curdled).

6-Fold in dry ingredients: Gradually fold dry ingredients into wet mixture with a spatula just until no streaks remain; do not overmix.

7-Add poppy seeds: Fold in poppy seeds (soak in milk beforehand for extra flavor if desired).

8-Divide batter: Divide batter evenly between the prepared pans.

9-Bake: Bake for 33–38 minutes until a toothpick inserted in center comes out clean or with moist crumbs.

10-Cool and optional syrup: Cool cakes in pans for 15–20 minutes, then invert onto a wire rack. Optionally brush warm layers with simple syrup (equal parts sugar/water plus lemon juice) for extra moisture.

11-Beat butter for frosting: Beat butter on medium-high speed until light and fluffy, about 2 minutes.

12-Add powdered sugar: Gradually add powdered sugar, one cup at a time, mixing on low until incorporated; scrape bowl as needed.

13-Add cream cheese: Add cold cream cheese, vanilla extract, and lemon juice; mix on medium speed just until smooth (do not overmix).

14-Adjust consistency: If frosting is lumpy, whisk on high briefly; for thicker consistency, add extra powdered sugar.

15-Level cake layers: Once completely cool, level the tops of the cake layers with a serrated knife if they domed.

16-Fill first layer: Place one cake layer on a stand, spread a generous amount of frosting on top.

17-Stack and crumb coat: Top with second layer, apply a thin crumb coat over the entire cake, and refrigerate 15 minutes to set.

18-Frost cake: Apply remaining frosting, smoothing the sides and top with a scraper or offset spatula.

19-Decorate: Optionally pipe frosting swirls around the top edge using a star tip and sprinkle extra poppy seeds.