Ingredients:

  • 300g cake flour
  • 250g granulated cane sugar
  • 15g Dutch-processed cocoa powder
  • 1 tsp baking soda
  • ½ tsp fine sea salt
  • 240ml buttermilk, room temperature
  • 60g whole milk Greek yogurt
  • 180ml vegetable oil
  • 2 large eggs, room temperature
  • 1 tsp distilled white vinegar
  • 2 tsp vanilla bean paste
  • 1 tsp purple gel food coloring
  • 225g unsalted grass-fed butter, softened
  • 350g low-sugar powdered sugar, sifted
  • 45ml heavy cream
  • 1 tbsp vanilla bean paste
  • 1 pinch salt

Instructions:

  1. Preheat your oven to 175°C (350°F). Grease two 20cm round cake pans and line the bottoms with parchment paper.
  2. Whisk together 300g cake flour, 250g sugar, 15g cocoa, 1 tsp baking soda, and ½ tsp salt. Sift until the mixture looks like fine dust.
  3. In a separate bowl, whisk 180ml oil, 2 eggs, 240ml buttermilk, and 60g Greek yogurt until completely smooth and pale.
  4. Stir in 1 tsp vinegar, 2 tsp vanilla bean paste, and 1 tsp purple gel color into the wet mixture. The color should look slightly darker than your desired final result.
  5. Fold the dry ingredients into the wet in three batches. Stop the moment you see no more white streaks.
  6. Divide the batter equally and bake for 35 minutes until a toothpick comes out with only a few moist crumbs.
  7. Let the cakes rest in the pans for 10 minutes, then invert onto a wire rack.
  8. Beat 225g softened butter for 5 minutes until it looks nearly white and doubled in volume.
  9. Gradually add 350g powdered sugar, 45ml heavy cream, and 1 tbsp vanilla bean paste. Whisk on high until it resembles a silky cloud.
  10. Layer the cake with a thick spread of frosting, then coat the outside. Refrigerate for 30 minutes before serving to set the structure.