Lemon Curd Trifle with Fresh Berries

large egg yolks

sugar

lemons, zested and juiced

unsalted butter, cut in chunks

fresh strawberries, stemmed and halved lengthwise

fresh blueberries

fresh blackberries

sweetened whipped cream

prepared lemon pound cake, sliced

Limoncello or Grand Marnier liqueur (optional)

Fresh mint leaves, for garnish