Wash and dry the strawberries and raspberries. Hull the strawberries and cut them into quarters. Take 5.3 oz of strawberries and 3.5 oz of raspberries, cook them for about 10 minutes with 1.8 oz of sugar and 3.4 fl oz of water. Blend and strain this coulis through a fine sieve, add the liqueur, and let it chill in the refrigerator.
Dissolve 3.5 oz of sugar in a saucepan with 5 fl oz of water, and cook until you obtain a syrupy consistency.
Separate the egg whites from the yolks, and beat the yolks with an electric mixer while slowly pouring in the sugar syrup. Continue beating until the mixture is pale and thick.
Beat the egg whites until stiff peaks form, and gently fold them into the egg yolk and sugar mixture. Whisk the mascarpone to loosen it, then fold it into the mixture.
Dip some ladyfinger biscuits into the coulis and line the bottom of a tall glass dish. Layer with some red berries, then cover with mascarpone cream.
Repeat the process until all ingredients are used, finishing with a layer of red berries, and refrigerate for 2 hours. Decorate with small meringues just before serving.