In a medium saucepan, combine the whole milk, 1/4 cup of granulated sugar, the cinnamon stick, and the lemon peel. Bring to a gentle simmer over medium heat, then remove from heat and let it steep for 5 minutes to infuse the flavors.

Arrange the stale bread slices in a single layer in a shallow baking dish. Strain the warm infused milk over the bread slices, ensuring they are completely submerged, and let them soak for 5 minutes until soft but still holding their shape.

While the bread soaks, beat the eggs in a wide, shallow bowl until smooth. In a separate small bowl, combine the remaining 1/4 cup of sugar with the ground cinnamon to create the coating.

Heat the olive oil in a large skillet over medium-high heat until hot but not smoking, which should take about 2 to 3 minutes.

Carefully lift one soaked slice of bread at a time, let any excess milk drip off, and dip both sides into the beaten egg to coat thoroughly.

Place the coated bread directly into the hot oil and fry for 2 to 3 minutes per side until they turn a beautiful golden brown and develop a crispy crust.

Transfer the fried torrijas to a paper towel-lined plate to drain for 30 seconds, then immediately dredge each side in the cinnamon-sugar mixture while still warm before serving.