Ingredients

For the Shortcrust Pastry

• 1¾ cups all-purpose flour (250 g)
• ⅓ cup unsalted butter (70 g), cold and cubed
• ⅔ cup granulated sugar (125 g)
• 1 large egg
• 2 tablespoons milk
• Zest of 1 lemon
• Pinch of salt

For the Limoncello Custard

• 1¼ cups whole milk (300 ml)
• 4 large eggs
• ⅔ cup granulated sugar (130 g)
• ⅓ cup all-purpose flour (40 g)
• Zest of 1 lemon
• 2 tablespoons limoncello liqueur (30 ml)

For the Sponge Cake Topping

• 1 cup all-purpose flour (140 g)
• 3 large eggs
• ½ cup granulated sugar (100 g)
• 3 tablespoons unsalted butter, melted (40 g)
• 1 teaspoon baking powder
• Zest of 1 lemon
• Pinch of salt

👩‍🍳 Method

Step 1: Make the Limoncello Custard

1. In a saucepan, heat milk and lemon zest until just about to boil. Remove from heat.
2. In a separate bowl, whisk eggs and sugar until light.
3. Stir in the flour to form a smooth paste.
4. Slowly pour in the hot milk while whisking constantly.
5. Return the mixture to the saucepan and cook over medium heat until it thickens into a custard.
6. Remove from heat and stir in limoncello. Cover with plastic wrap and let cool completely.

Step 2: Prepare the Shortcrust Dough

1. In a large bowl, combine flour, sugar, and salt.
2. Add butter and mix with a pastry blender or your fingers until crumbly.
3. Add the egg, milk, and lemon zest. Mix until a dough forms.
4. Shape into a ball, wrap in plastic wrap, and refrigerate for 30 minutes.

Step 3: Prepare the Sponge Cake Topping

1. Beat eggs and sugar until tripled in volume and pale in color.
2. Fold in lemon zest, flour, salt, and baking powder.
3. Gently stir in melted butter just until incorporated.

Step 4: Assemble and Bake

1. Preheat oven to 350°F (180°C).
2. Roll out the chilled pastry and press into a greased 9-inch (24 cm) tart or springform pan.
3. Pour the cooled custard into the base and spread evenly.
4. Top with the sponge batter, spreading gently over the custard.
5. Bake for 30–40 minutes or until the top is golden and springs back when touched.
6. Let cool before serving. Dust with powdered sugar if desired.