I preheat the oven to 350°F (175°C) and ensure my 10-inch tube pan is clean and ungreased to allow the batter to climb.

In a large bowl, I beat 6 egg whites with ½ tsp cream of tartar and ¼ tsp salt using an electric mixer until soft peaks form. I gradually add ½ cup granulated sugar, beating until stiff, glossy peaks form. I fold in 1 tsp vanilla extract. I sift ¾ cup cake flour and ¼ cup sugar together, then gently fold into the egg whites in three additions, preserving volume for Daffodil Cake.

In another bowl, I beat 4 egg yolks with ½ cup granulated sugar until pale and thick. I mix in 1 tsp vanilla extract and 1 tsp lemon zest. I sift ½ cup cake flour over the mixture and fold gently until combined.

I spoon half the angel food batter into the tube pan, then add the sponge batter, and top with the remaining angel food batter. For a marbled effect, I gently swirl with a spatula. I smooth the top lightly.

I bake for 35–40 minutes until the top is golden and springs back when touched. I immediately invert the pan onto a sturdy bottle to cool completely, preventing collapse. Once cooled, I run a knife around the edges to release the cake.

I beat 1 cup softened butter until creamy, then gradually add 3 cups sifted powdered sugar, ¼ cup heavy cream, 1 tsp vanilla extract, and a pinch of salt, beating until smooth and fluffy.

I spread the buttercream evenly over the cooled cake, creating soft swirls with a spatula. For a spring touch, I sprinkle yellow sanding sugar or add edible flowers like daffodils.

I slice with a serrated knife and serve at room temperature, enjoying the light, citrusy flavors with a spring beverage.