Step 1

Preheat oven to 350°. Coat a 9" cake pan with nonstick spray and line bottom with a parchment paper round. Whisk flour, baking powder, baking soda, salt, cinnamon, ginger, and nutmeg in a large bowl to combine.

Step 2

Combine granulated sugar, brown sugar, oil, honey, egg, and egg yolk in another large bowl. Scrape in seeds from vanilla bean; discard pod. Using an electric mixer on medium speed, beat mixture until pale and thickened, about 4 minutes. Reduce speed to medium-low and gradually pour in orange juice and whey. Beat until frothy, about 2 minutes. Reduce speed to low and gradually add dry ingredients; beat just until smooth and homogenous (it will be thin, like pancake batter).

Step 3

Pour into prepared pan and bake until cake is golden brown and center springs back when gently pressed (a cake tester will not come out clean), 45–55 minutes. Transfer to a wire rack and let cool in pan, 20 minutes. Run a knife around edges of cake to loosen and invert onto rack; let cool completely.

Step 4

Do Ahead: Cake can be baked 3 days ahead. Store tightly wrapped at room temperature.

Step 5

Using an electric mixer on medium-high speed, beat cream cheese and butter in a medium bowl until smooth. Add powdered sugar, lemon zest, and salt and scrape in seeds from vanilla bean; discard pod. Beat on low speed until mixture is very light and thickened, about 2 minutes; scrape down sides of bowl. With motor running, add coconut cream by the tablespoonful and beat until very soft peaks form (save coconut milk for another use).

Step 6

Pile frosting on top of cake and spread to edges (it’s okay if it cascades over the sides). Decorate with bee pollen, fennel fronds, flowers, and berries, if desired.