2 cups mixed sliced berries, such as strawberries, raspberries, blueberries, and blackberries
Thickly peeled zest of 2 lemons
For the lemon cream and trifle assembly:
1 cup heavy whipping cream
¼ cup sour cream
¼ cup lemon sugar syrup (see recipe in Directions)
½ teaspoon vanilla extract
8 ounces prepared vanilla cake, crumbled into medium pieces (about 4 cups)
Mint, for garnish
Make the lemon sugar syrup: Bring the sugar, water, and lemon zest to a boil over medium heat in a small saucepan and boil until the sugar is completely dissolved and the syrup thickens slightly, about 3 minutes. Remove from the heat and stir in the lemon juice. Cool completely and remove any big pieces of lemon zest. Place the berries in a bowl and toss with ¼ cup of the lemon syrup; set aside while you make the cream.
Make the lemon cream: Using a stand mixer fitted with the whisk attachment (or a hand mixer or just a whisk and bowl), beat the heavy cream to stiff peaks, 2 to 3 minutes. Add the sour cream, ¼ cup lemon sugar syrup, and vanilla, and whisk back to stiff peaks, 1 to 2 minutes.
Assemble the trifle: In a bowl, combine the crumbled cake with ¼ cup each of the lemon syrup and the lemon cream to moisten. Spoon ¼ each of the cake, cream, and berries into four glasses in that order. When putting in the cake layer, make sure the outer ring of cake uses the prettiest pieces since you’ll see them most prominently when building layers. It can also be built in one medium trifle dish or glass bowl for serving a crowd. You can eat them right away, but ideally you let the trifles sit in the fridge overnight. (If you do this, add the fruit right before you serve.) Garnish with mint and lemon zest.