To make the lemon curd: Bring a pot of water to a simmer over medium-low heat. Combine the egg yolks, sugar, lemon juice, and zest in a metal or glass heat-resistant bowl and whisk until smooth. Set the bowl over the simmering water, without letting the bottom touch, and continue to whisk. Keep working-out that arm and whisk it vigorously for a good 10 minutes, until the curd has doubled in volume and is very thick and yellow. Don't let it boil. Remove the bowl from heat and whisk in the butter, a couple of chunks at a time, until melted. Refrigerate until the custard is cold and firm.
To build the trifle: put the berries in a mixing bowl and toss them together so they are evenly distributed. Fold the whipped cream into the chilled lemon curd to lighten it up into a mousse. Line a glass trifle bowl with pieces of pound cake to fit. Drizzle or brush the cake with the Limoncello, spoon a layer of the lemon curd over the cake, and then a layer of mixed berries. Repeat the layers until the ingredients are used up, the last layer looks best if it's the berries. Chill before serving. Garnish with fresh mint.
Recipe courtesy of Tyler Florence