Add egg yolks one at a time, beating after each addition and scraping the sides.
Add vanilla, pineapple and brazil nuts.
Beat egg whites until stiff but moist and fold into mixture gently.
Place a layer of cake in a dish, then a layer of pineapple-butter mixture; continue to layer until all the cake and mixture are used up, ending with the pineapple mixture.
Cover with foil and freeze for 24 hours.
When ready to use take out and thaw for a 10 minutes. Garnish with whipped cream, a maraschino cherry and sprig of mint,or candied orange pieces -- whatever suits you.
Variation: drained peaches or ripe mangoes could be substituted for the pineapple. I have only ever made it with pineapple.
How does a frozen dessert transform into a sliceable cake without gelatin or starch? Butter and eggs provide the structural backbone when combined with sugar. Creaming the butter and icing sugar incorporates tiny air pockets. Adding egg yolks one by one creates a stable emulsion that prevents the high fat content from breaking. Folding in whipped egg whites introduces delicate aeration, ensuring the rich mixture retains a light mouthfeel after freezing.
Chemical Reactions in Cold Fats
Pineapple contains the enzyme bromelain, which breaks down proteins. The high proportion of dairy fat in the butter and whipped cream moderates this activity during the 24-hour freezing window. Slicing the lemon sponge cake precisely to one-inch thickness guarantees uniform absorption of moisture from the fruit. Thoroughly beating the egg whites until stiff but moist prevents the mixture from weeping liquid ice crystals as it sets.
Transforming Leftovers Over Time
Thawing the dessert for precisely 10 minutes softens the butter crystals just enough for clean portioning. Second-day refrigeration yields a denser, pudding-like crumb as the sponge fully hydrates from the pineapple juices. Substituting drained peaches or ripe mangoes requires matching the volume to maintain the correct fat-to-fruit ratio.