Beat egg yolks with sugar and add mascarpone. Beat for a few minutes with it, add lemon juice and then stir gently with the pre-whipped cream. In another bowl, beat egg whites to snow.
Using a spatula, stir the mixture again. Prepare a rectangular baking dish and arrange a row of biscotti.
Top gently with pineapple juice and spread the compote and cream. Sprinkle with plenty of coconut. Make decorations with pineapple and store for a few hours in the refrigerator.