For coating and frying:
1. Place 3 cups of milk, sugar, cinnamon stick, and lemon peel and pinch of salt in a saucepan and bring to a simmer over low heat.
2. Meanwhile in a bowl, whisk cornstarch with the remaining 1 cup of milk. Whisk until smooth.
3. Remove cinnamon stick and lemon peel from the hot milk. Pour the cornstarch mixture to the hot milk and heat over low-medium heat, stirring constantly, until thickens. Remove from heat, stir in vanilla extract.
4. Pour the mixture into a pan lined with parchment paper. Cover with plastic wrap, let cool to room temperature, then refrigerate for at least 4 hours.
5. When chilled, cut into squares.
6. Prepare the coating: in one bowl beat 2 eggs, in the second bowl put flour, in the second plate/bowl mix sugar and cinnamon.
7. Coat milk squares in flour, then dip in beaten eggs.
8. Fry in hot oil for about 1-2 minutes on each side, until golden.
9. Transfer to a paper towel to drain, then coat with sugar-cinnamon mixture. Serve warm!