No-Churn Lemon Tiramisu Ice Cream

Cube the butter, then place it into a small mixing bowl. Place a fine mesh sieve over the butter and set it aside.
Add the egg, sugar, lemon zest, lemon juice, and salt to a medium-sized saucepan. Whisk the mixture vigorously until it's smooth.
Place the mixture over medium heat, stirring constantly until it thickens (~3-5 min.)
Remove the mixture from the heat and pour it through the fine mesh sieve over the butter. Mix together the curd and butter until the butter has completely melted, then set the curd in the freezer to cool while you make the ice cream.

Add the mascarpone, vanilla, salt, and heavy whipping cream to a large mixing bowl. Beat with a hand mixer or with a stand mixer fitted with the whisk attachment, until stiff peaks form.
Pour the sweetened condensed milk into the whipped cream. Gently fold until the mixture is cohesive. Set aside.

Add the lemon juice and sugar to a small and shallow mixing bowl. Stir the mixture, then microwave it for 30 seconds and stir it again, until the sugar has dissolved.
Cut or break the ladyfingers into thirds.

Pour ½ of the ice cream into a 1 lb. loaf pan. Dollop ~⅔ of the lemon curd over the ice cream, then gently swirl it into the ice cream.
Quickly dip ~2/3 of the ladyfinger pieces into the lemon juice mixture and gently press them into the ice cream.
Pour the rest of the ice cream into the pan and smooth it out into an even layer. Dollop the remaining lemon curd on top and swirl it into the ice cream.
Dip the rest of the ladyfinger pieces into the lemon juice mixture and gently press them into the ice cream.
Cover the pan with plastic wrap and set it in the freezer for at least 4 hours, or until the ice cream is firm. Scoop, serve, and enjoy!