In a medium saucepan, combine milk, cream, sugar, lemon zest, and cinnamon sticks. Heat over medium until steaming but not boiling. Remove from heat, cover, and steep for 10 minutes.
In a bowl, whisk egg yolks and cornstarch until smooth.
Slowly pour ½ cup of the warm milk mixture into the egg mixture, whisking constantly.
Return the tempered egg mixture to the saucepan. Cook over medium-low heat, whisking, until thickened (5–7 minutes). Remove cinnamon sticks.
Pour custard into lightly greased ramekins. Cover and refrigerate for at least 4 hours or until firm.
Unmold onto serving plates. Dust with ground cinnamon and sprinkle shredded coconut. Serve chilled.