01 -
Preheat oven to 350°F. Grease three 8-inch straight-edge cake pans. Line with parchment paper and grease again.
02 -
In a medium bowl, sift together the flour, baking soda, baking powder, and salt. Whisk until fully blended.
03 -
In a stand mixer or with a handheld mixer, cream the butter, sugar, and orange zest until light and fluffy, about 5 minutes.
04 -
Whisk in eggs, egg whites, vanilla extract, and orange extract at high speed until combined, for about 2 minutes. Scrape down the sides as needed.
05 -
On a low speed, add the flour mixture to the wet ingredients and mix until just combined. Then, still on low, pour in the buttermilk and orange juice, mixing until just incorporated.
06 -
Pour the batter evenly into the prepared pans. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Cool on a wire rack for at least 1 hour before frosting.
07 -
In a stand mixer or with a handheld mixer, whisk the butter and cream cheese until light and creamy. Sift in powdered sugar. Add the orange zest, orange extract, vanilla paste, and heavy cream. Whisk until smooth and fluffy. Adjust consistency with powdered sugar or heavy cream as needed.
08 -
Place one cooled cake layer flat side down on a plate or stand. Spread about 1 cup of frosting on top using an offset spatula. Add the second cake layer and top with another 1 cup of frosting. Place the final layer flat side up for a level surface. Lightly frost the rest of the cake with remaining frosting.
09 -
Chill the cake in the refrigerator for 10 minutes. Remove, garnish with orange slices, sage leaves, and sanding sugar. Chill again for 30-60 minutes until the frosting sets.
10 -
Cover the cake tightly and store in the refrigerator for 4-5 days.