In a saucepan, combine the sweetened condensed milk and evaporated milk. Cook over medium heat, stirring constantly, until thickened (about 20 minutes).
Remove from heat and let cool slightly. Whisk in the egg yolks until well combined.
In a separate saucepan, combine the sugar and port wine. Cook over medium heat until it reaches a syrupy consistency (about 10 minutes).
In a mixing bowl, beat the egg whites until stiff peaks form. Gradually add the port wine syrup, continuing to beat until glossy and stiff.
Divide the milk mixture into serving glasses. Top with the meringue and sprinkle with ground cinnamon.