In a saucepan, over medium heat, combine the cinnamon stick, lemon peel, 3/4 cup of the sugar, and 2 1/2 cups of milk. Bring to a simmer and cook for 30 minutes. Remove the cinnamon stick and lemon peel. In a small mixing bowl, combine the remaining milk and the cornstarch. Whisk well. Slowly whisk the cornstarch mixture into the hot milk mixture. Bring to a boil and cook for 8 minutes, whisking constantly. Remove from the heat and pour into a greased 8-inch baking dish. Cool completely. Cover and refrigerate until well chilled. Cut the custard into 2-inch triangles. Combine the remaining 1/4 cup sugar and cinnamon. Mix well. Dredge the triangles in the flour, coating completely. Dip each triangle in the egg wash, letting the excess drip off. Dredge the custards back into the flour, coating completely. In a large saute pan, over medium heat, add the oil. Lay the triangles in the hot oil and pan-fry until golden on both sides, about 3 minutes. Remove and drain on paper towels. Season with the cinnamon sugar mixture. Repeat the above process with the remaining triangles. Serve warm.