Mix eggs, yolks, sugar, lemon juice and zest and cook over medium heat until thickening while whisking constantly; strain through a sieve and mix in butter until melted; cover with plastic wrap and refrigerate for about 2 hours
Beat heavy whipping cream into stiff peaks
Mix mascarpone with 1 cup lemon curd and fold in whipped cream
Make the syrup by bringing all ingredients to boil and slightly cool
Layer some of the lemon tiramisu mixture on the bottom of a casserole dish, dip ladyfingers on both sides in syrup and layer them over, spread more tiramisu mixture and repeat one more time
Cover and refrigerate for a few hours or overnight
The next day spread the remaining lemon curd on top, decorate with lemon slices and optional flowers, then enjoy
