- If using strawberries, hull and slice them. Place them in a bowl and add the other berries. Add the superfine sugar, orange juice and liqueur and stir gently to mix. Set aside to macerate for at least 1 hour or up to 3 hours.
- Cut the pound cake into 1-inch cubes and set aside until ready to assemble the trifle. You should have about 6 cups.
- In a large bowl, using an electric mixer on medium-high speed, beat together the cream, confectioners' sugar and vanilla until soft peaks form, about 3 minutes. In a separate bowl, using clean beaters and with the mixer on medium-high speed, beat the mascarpone until soft. Using a rubber spatula, fold the whipped mascarpone and the lemon zest into the whipped cream until evenly blended.
- Select a footed glass trifle bowl 9 to 10 inches in diameter and 5 inches deep. Alternatively, use a large flat-bottomed glass bowl. Arrange a single layer of the cake cubes in the bottom of the bowl. Spoon one-third of the macerated berries over the cake and then spread one-third of the mascarpone mixture over the berries. Repeat the layers twice, finishing with a layer of the mascarpone mixture. Cover with plastic wrap and refrigerate for at least 4 hours or up to 24 hours to allow the flavors to marry.
- Just before serving, garnish the trifle with whole berries and mint.