Make the cream cheese Swiss meringue buttercream

• Warm the egg whites and caster sugar in a saucepan over a bain-marie until the sugar dissolves
• Whisk to a stiff meringue, then beat in the softened butter until smooth and silky
• Beat in the cream cheese until just combined, keeping the buttercream firm

Fill and stack the cake

• Place the first red velvet sponge layer on the cake board
• Spread the cream cheese buttercream filling over the sponge
• Top with the second sponge layer and press gently

Make the vanilla Swiss meringue buttercream

• Warm the egg whites and caster sugar in a saucepan over a bain-marie until the sugar dissolves
• Whisk to a stiff meringue, then beat in the softened butter until smooth
• Flavour with the vanilla extract

Apply the final coat

• Cover the cake with the vanilla buttercream
• Smooth the top and sides with the offset spatula for a clean finish

Pipe the black decorations

• Colour part of the vanilla buttercream with the black food colouring
• Pipe small hearts all around the sides of the cake
• Pipe a shell border around the top and bottom edges and write a happy birthday message on top

Add the gold finish

• Scatter the gold sprinkles over the cake for a golden shimmer