Portuguese Custard Tarts

Instructions

1. Prepare the pastry
   Roll the puff pastry sheet tightly into a log, starting from the shorter edge. Cut the log into 12 equal pieces, about 1-inch thick. Place each piece cut-side down into the cups of a non-stick 12-cup muffin tin. Using wet fingers, press the dough to flatten against the bottom and sides of each cup, creating a thin pastry shell. Refrigerate for 20 minutes.
2. Make the custard base
   In a medium saucepan, combine the milk, lemon peel and cinnamon stick. Heat over medium-low until just simmering, then remove from heat and let infuse for 10 minutes. Remove and discard the cinnamon stick and lemon peel.
3. Prepare the sugar syrup
   In a separate saucepan, combine the sugar with 100ml water. Bring to a boil without stirring, then continue to boil until it reaches 220°F (100°C) on a candy thermometer, about 5 minutes. Remove from heat and let cool slightly.
4. Finish the custard
   In a large bowl, whisk the egg yolks, cornstarch, vanilla, and salt until smooth. Gradually whisk in the warm milk mixture. Then, slowly stream in the hot sugar syrup while continuously whisking. Return the mixture to the saucepan and cook over medium heat, stirring constantly until thickened, about 3-4 minutes. Transfer to a bowl and cover with plastic wrap directly on the surface to prevent a skin from forming.
5. Preheat and assemble
   Preheat your oven to 500°F (260°C) or as high as your oven will go. Remove the muffin tin from the refrigerator. Fill each pastry shell about 3/4 full with the custard mixture. Be careful not to overfill.
6. Bake the tarts
   Place the muffin tin on the top rack of your oven and bake for 12-15 minutes, until the pastry is golden and crisp and the custard develops dark caramelized spots on top. Watch carefully to prevent burning.
7. Cool and serve
   Allow the tarts to cool in the tin for 5 minutes, then carefully remove and transfer to a wire rack. They can be enjoyed warm or at room temperature. Dust with ground cinnamon if desired before serving.