Leche Frita: Spanish Fried Milk Custard

In a medium saucepan, combine 700 ml (2 3/4 cups + 2 tbsp) of the milk with the cinnamon stick and lemon zest, if using. Warm gently over medium-low heat until barely simmering, then remove from heat and let steep for 10 minutes. Remove the cinnamon and zest.

In a bowl, whisk the cornstarch, flour, and 100 ml (1/3 cup + 1 tbsp) of the remaining cold milk into a smooth paste. Add the egg yolks and whisk until fully combined.

Return the infused milk to medium-low heat and whisk in the sugar. Once the sugar dissolves, pour in the egg yolk mixture in a steady stream, whisking constantly. Cook, stirring continuously with a whisk or wooden spoon, until the mixture thickens to a dense pastry cream that holds a trail. This should take 8–10 minutes; do not let it boil hard.

Lightly grease a 20 x 20 cm (8 x 8 inch) square baking dish with the butter. Pour in the hot custard and smooth the top with a spatula. Let cool slightly, then cover directly with plastic wrap and refrigerate for at least 4 hours or overnight until completely firm.

Run a knife around the edge of the chilled custard and invert it onto a board. Cut into 12 squares, about 5 cm (2 inches) each. Set out three shallow dishes: flour, beaten eggs, and breadcrumbs. Dredge each square in flour, then egg, then breadcrumbs, pressing gently so the coating adheres.

Heat the frying oil in a deep skillet over medium-high heat until it reaches 180°C (350°F). Fry the coated squares in batches, without crowding, for 2–3 minutes per side until deep golden and crisp. Transfer to a plate lined with paper towels.

Dust the warm leche frita generously with cinnamon sugar and serve immediately, while the outside is still crisp and the centre is soft and molten.