Make the lemon cake

• Preheat the oven to 325 F. Grease and flour three 8 inch round cake pans (if you’re making a smaller cake make half the recipe and use two 6 inch round pans).
• Set the eggs in a bowl of hot water to come up to room temperature.
• Pour the sugar into the bowl of a stand mixer and over it zest the lemons. Rub the lemon zest into the sugar with your fingers until the sugar feels like wet sand, this helps release the oils and flavor. Add the vanilla and salt.
• Add the eggs to the bowl and beat until very light and fluffy, about 4-5 minutes. With the mixer on, slowly pour in the oil. Beat until combined.
• Over the bowl, sift in the cake flour and add the leavening. With the mixer on, slowly pour in the buttermilk/kefir and the fresh lemon juice. Stop mixing as soon as the flour is incorporated. Use a rubber spatula to scrape down the bowl and ensure the batter is evenly mixed. If you are adding the raspberries to the cake layers, stir in 1 cup of fresh berries.
• Divide the batter between the prepared cake pans. Bake until a cake tester comes out clean or the tops spring back, for 8 inch cakes this will take 30-45 minutes, for 6 inch cakes 25-35 minutes. Invert the cakes onto a cooling rack and allow to cool completely.

Make the raspberry buttercream and transfer to a piping bag.

Assemble the cake

• Slice the domed tops of the cakes so that you have even layers. Set one layer, face up on a cake turntable. Pipe a border around the cake then spread about 3 tablespoons of lemon curd over the cake. Add sliced raspberries on top, if desired.
• Place the second cake layer face down onto the cake and pipe another border, spread 3 more tablespoons of lemon curd and add fresh raspberries.
• Plate the third cake layer face down and pipe buttercream around all the cake sides and add a big dollop on top. Spread the buttercream over the cake and use a bench scraper to even out the sides. Decorate as desired, with fresh raspberries or by piping a pretty border on the sides.