Let’s bake this elegant cake:

1. Prepare Pans and Preheat Oven: Preheat the oven to 180°C (160°C fan/350°F/Gas Mark 4). Grease and line the bottoms of three 18cm (approx. 7-inch) diameter loose-bottomed sponge tins with parchment paper.

2. Make the Cake Batter:

• In a large bowl or stand mixer, beat the softened salted butter and golden caster sugar together until very light and creamy (3-5 minutes).
• Add the room temperature eggs one at a time, beating well between each addition. Adding a spoonful of the flour mixture with each egg can help prevent curdling.
• Gently fold through the self-raising flour until just combined. Do not overmix.
• Stir through the lemon curd yogurt, lemon zest, and 3 tablespoons of the elderflower cordial.

3. Bake the Cake Layers:

• Divide the mixture evenly between the prepared tins. Smooth the tops.
• Bake for 30 minutes, or until a skewer inserted into the center comes out clean.

4. Prepare Soak and Cool Cakes:

• While cakes are baking or still warm, combine the juice of 1 lemon and the remaining 2 tablespoons of elderflower cordial to make the syrup soak.
• Once cakes are baked, let them cool in the tins for 15 minutes.
• Prick the warm sponges all over with a skewer and spoon the lemon-elderflower syrup evenly over them.
• After 15 minutes, carefully remove the cakes from the tins (using the loose bottoms) and cool completely on a wire rack. (Cooled sponges can be wrapped and frozen for up to 1 month).

5. Make the Elderflower Buttercream:

• In a large bowl or stand mixer, beat the softened salted butter until very soft and creamy.
• Gradually beat in the sifted icing sugar in two batches until fully incorporated.
• Mix through the 3 tablespoons of elderflower cordial until smooth and fluffy.

6. Assemble the Cake:

• Place one cooled (and soaked) sponge layer on a cake stand or serving plate.
• Spread some of the elderflower buttercream evenly over the layer.
• Spread 2 tablespoons (half) of the lemon curd over the buttercream.
• Top with the second cake layer. Repeat with more buttercream and the remaining 2 tablespoons of lemon curd.
• Top with the final sponge layer.

7. Frost the Exterior (Semi-Naked Style):

• Cover the whole cake (top and sides) with the rest of the icing.
• Using a palette knife or bench scraper, skim the sides to remove most of the frosting, allowing some of the cake layers to show through for a “semi-naked” look. Keep the top layer of frosting smooth. (The cake can be assembled up to this point a day ahead and refrigerated).

8. Decorate and Serve:

• Just before serving, decorate the cake with fresh spring flowers (ensure they are edible/food-safe if placing directly on the cake) and candied lemon slices, if using.
• Serve slices at room temperature. Leftovers keep for 3-4 days in an airtight container.

Take your time with assembly for a beautiful result!