Bake a lemon cake in a parchment lined jelly roll sheet pan, allow to cool while you prepare the other items (once cool, you will cut out shapes to fit neatly into your trifle container)

Zest 1 lemon and combine with 1-2 tablespoons of sugar in order to candy the zest. Rest in freezer, until ready to garnish

Juice the zested lemon and prepare a simple lemon syrup by warming juice, water and sugar on the stove. Reserve for assembly

Whip approximately 4 cups of whipping cream. Allow to rest in refrigerator while you prepare the mousse. Don't add sugar yet

Prepare the lemon mousse, steps 6-10

Dissolve gelatin in cold water, in a small pot that can later go on the stove. Let stand for at least 5 minutes

Beat the 4 egg yolks and 4 tablespoons of sugar until light and fluffy. Carefully blend in juice and zest of 2 remaining lemons

Melt dissolved gelatin over low heat. Add to the egg mixture, stirring well. (Once you add the gelatin you must be ready with the whipped cream and egg whites quickly or you will have lumpy mousse)

Take about 3/4 of the whipped cream from the refrigerator and fold into the egg mixture

Beat the egg whites until stiff peaks form. Fold into egg mixture

If desired, add any powdered sugar to remaining whipped cream to taste

Assemble trifles -- Layer cake, brush with simple syrup (prevents cake from being too dry), mousse, cake, syrup, mousse,etc. until containers are full, try to end with mousse. Add large dollop of sweetened whipped cream to the top. Finish with candied lemon zest

Chill for 2-20 hours prior to serving