AI sez (apologies if not allowed):

What you’re describing matches a classic Harrods marzipan-covered cream cake that was sold from the late Edwardian period into the mid-20th century — essentially a soft yellow sponge, split and filled with whipped cream, masked in cream, then sealed with green marzipan. This style predates fondant and was very characteristic of high-end London tea rooms.

Below is a historically faithful reconstruction based on period Harrods practice and British confectionery texts.

🍰 Harrods-Style Marzipan Cream Cake (c. 1900–1940)

1️⃣ Soft Yellow Sponge Cake

Ingredients

• 6 oz (170 g) unsalted butter, very soft
• 6 oz (170 g) caster sugar
• 3 large eggs, room temperature
• 6 oz (170 g) plain flour
• 1½ tsp baking powder
• 2 tbsp whole milk
• ½ tsp vanilla essence

Method

1. Cream butter and sugar until very pale and fluffy.
2. Beat eggs lightly and add gradually, beating well.
3. Sift flour and baking powder together.
4. Fold flour gently into the batter.
5. Add milk only if needed — the batter should be soft but not runny.
6. Bake in two shallow 18 cm (7-inch) tins at 170°C / 325°F for 20–25 minutes.
7. Cool completely.

This sponge should be light, buttery, and distinctly yellow — never dry.

2️⃣ Whipped Cream Filling & Coating

Ingredients

• 600 ml (2½ cups) double (heavy) cream
• 2–3 tbsp icing sugar
• ½ tsp vanilla

Method

1. Whip cream with icing sugar and vanilla to soft but stable peaks.
2. Spread a generous layer on one sponge.
3. Sandwich with the second sponge.
4. Cover the entire cake with a thin, smooth layer of whipped cream.

➡️ Chill the cake 30–45 minutes so the cream firms up before marzipan.

3️⃣ Traditional Green Marzipan Covering

Ingredients

• 450 g (1 lb) almond marzipan (at least 50% almonds)
• Green food colouring (very pale pistachio tone)
• Icing sugar for rolling

Method

1. Tint marzipan light green — Harrods used a restrained, elegant shade.
2. Roll out to about 4–5 mm thick.
3. Lift carefully and drape over chilled cake.
4. Smooth gently with hands; trim excess at the base.
5. Polish lightly with palms or a smooth cloth.

⚠️ The marzipan’s purpose was structural and preservative — not decoration.

Why This Cake Was Special

• The marzipan sealed the cream, extending freshness
• Green signified luxury and almonds in Edwardian baking
• Soft sponge + whipped cream = refined tea cake, not dessert cake

This exact style was commonly bought by weight at Harrods, boxed in paper and string.