Ingredients:

  • 375 g all-purpose flour
  • 9 g baking powder
  • 3 g fine salt
  • 225 g unsalted butter, softened to room temperature
  • 350 g granulated sugar
  • 12 g lemon zest (from about 2 lemons)
  • 4 large eggs (200 g), room temperature
  • 1 tsp alcohol-free vanilla extract
  • 45 ml fresh lemon juice
  • 240 ml buttermilk, room temperature
  • 240 g raspberries, fresh or frozen
  • 67 g granulated sugar
  • 15 ml fresh lemon juice
  • 12 g cornstarch mixed with 15 ml cold water
  • 225 g unsalted butter, softened
  • 480 g powdered sugar, sifted
  • 30 ml fresh lemon juice
  • 2 g lemon zest
  • 15 ml heavy cream
  • 1 pinch salt

Instructions:

  1. Preheat the oven to 180°C (350°F). Grease four 4-inch round cake pans and line the bottoms with parchment.
  2. Whisk the flour, baking powder, and fine salt in a bowl. Set aside.
  3. Rub the lemon zest into the granulated sugar with your fingertips until the sugar looks damp and fragrant.
  4. Beat the butter and lemon sugar on medium-high speed for 3 to 4 minutes, until pale and fluffy.
  5. Add the eggs one at a time, beating well after each. Mix in the alcohol-free vanilla and the 45 ml lemon juice. The batter may look slightly curdled; this is normal.
  6. On low speed, add the flour mixture in three additions, alternating with the buttermilk in two additions. Start and end with flour. Mix only until no dry streaks remain.
  7. Divide the batter evenly among the four prepared pans, about 120 ml each.
  8. Bake for 15 to 18 minutes, until a toothpick inserted in the center comes out clean and the tops spring back when lightly pressed. The edges should be golden and pulling slightly away from the pan.
  9. Cool the layers in their pans for 10 minutes, then turn them out onto a rack and cool completely.
  10. Repeat the baking with the remaining batter in two more batches, for 12 layers in total.
  11. Combine the raspberries, 67 g sugar, and 15 ml lemon juice in a saucepan over medium heat. Cook for 5 to 7 minutes, mashing the berries, until they soften and release juice.
  12. Stir in the cornstarch slurry and simmer for 1 to 2 minutes, stirring, until the filling bubbles, turns glossy, and is thick enough to coat a spoon.
  13. Pour the filling into a bowl and cool completely, about 30 minutes.
  14. Beat the 225 g butter until creamy and pale, about 2 minutes. Add the powdered sugar gradually, then the 30 ml lemon juice, lemon zest, heavy cream, and salt. Beat for 3 minutes, until light and smooth.
  15. Level each layer with a serrated knife if the tops domed. Place one layer on a cake board or small plate.
  16. Spread about 1 tablespoon of cooled filling evenly over the first layer, leaving a small border so it does not squeeze out.
  17. Top with the second layer and press gently. Refrigerate the assembled cakes for 1 hour so the filling sets.
  18. Spread a thin crumb coat of buttercream over each cake, then refrigerate for 15 minutes.
  19. Spread a smooth layer of the remaining buttercream over each cake. Garnish with fresh raspberries and a twist of lemon peel.
  20. Cut each cake in half to serve. Store frosted cakes in an airtight container in the refrigerator for up to 4 days, and bring to room temperature for 20 to 30 minutes before serving.