Prepare the Citrus Curd: Combine sugar and orange zest in a saucepan. Whisk in eggs, orange juice, cornstarch, and lemon juice. Cook over medium heat, stirring constantly, until thickened (about 10 minutes), then strain through a fine mesh and chill in the refrigerator.

Make the Cake Batter: Preheat your oven to 350°F (175°C). In a mixing bowl, whisk together the sugar and orange zest until fragrant. Add in the eggs and olive oil, mixing until smooth. In another bowl, combine the flour, baking powder, and baking soda. Gradually mix the dry and wet ingredients until just combined.

Bake the Cake: Pour the batter into a greased and parchment-lined 9" round cake pan. Bake for 35-40 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool in the pan for about 10 minutes before inverting onto a wire rack to cool completely.

Prepare the Whipped Cream: In a large bowl, beat the heavy cream with powdered sugar until medium-stiff peaks form. If desired, add a splash of vanilla or orange extract for extra flavor, then gently mix until combined.

Assemble the Cake: Once the cake is completely cooled, frost the top with the whipped cream, then generously dollop the chilled citrus curd on top. Decorate with additional orange zest and edible flowers for a stunning finish.