1. Preheat oven to 350°F (175°C). Grease three 8-inch round cake pans, line the bottoms with parchment, then grease and flour the parchment.

2. Rub the orange zest into the granulated sugar until the sugar becomes damp and fragrant. Beat the orange sugar with softened butter for 3–4 minutes until pale and fluffy.

3. Add the eggs one at a time, beating well after each addition and scraping the bowl as needed.

4. Whisk the cake flour, baking powder, and salt in one bowl. In another, combine the milk, orange juice, and vanilla bean paste.

5. Add the dry and wet mixtures to the butter mixture in three alternating additions, beginning and ending with the dry ingredients. Mix on low just until combined.

6. Divide the batter evenly between the prepared pans and smooth the tops. Bake for 26–30 minutes, until the cakes spring back lightly and a toothpick comes out clean or with a few moist crumbs.

7. Cool the cakes in their pans for 10 minutes. Turn them onto wire racks and allow them to cool completely.

8. For the curd, whisk orange juice, zest, sugar, egg yolks, whole eggs, and salt together in a saucepan while cold.

9. Cook over medium-low heat, whisking constantly for 8–10 minutes, until thick enough to coat the back of a spoon.

10. Remove from heat and whisk in the cold butter a few pieces at a time until smooth and glossy.

11. Strain the curd into a clean bowl. Press plastic wrap directly onto the surface and refrigerate for at least 2 hours.

12. For the frosting, beat the softened cream cheese and butter until smooth, about 2 minutes.

13. Gradually mix in the sifted powdered sugar. Add orange zest, orange juice, vanilla bean paste, and salt, then mix until smooth.

14. Whip the cold heavy cream separately until stiff peaks form. Gently fold it into the cream cheese mixture in two additions until no streaks remain.

15. Trim the cake layers if needed. Place the first layer on a serving plate and pipe a thick frosting border around the edge.

16. Spread about one-third of the chilled orange curd inside the frosting border. Add the second cake layer and repeat with frosting and curd, then place the final layer on top.

17. Cover the entire cake with a thin crumb coat and refrigerate for 20 minutes. Finish with the remaining frosting and decorate as desired.