Pour the milk into a 3-quart / 2.8 L saucepan with the cinnamon stick and lemon peel strips. Heat over medium until steaming but not boiling, about 5 minutes, then remove from heat and let it steep 10 minutes.

Meanwhile, whip the egg whites with the pinch of salt using a stand mixer to soft peaks, about 2 minutes. Add 100 g sugar gradually, a tablespoon at a time, and keep whipping to stiff, glossy peaks, 3 to 4 more minutes.

Return the milk to a bare simmer, just small bubbles at the edges. Using two spoons, scoop the meringue into egg-shaped dollops, about 8 total, and poach in batches of 3 to 4 so they don't touch, 2 to 3 minutes per side, until puffed and springy when pressed.

Lift the meringues out with a slotted spoon and drain on a clean towel. Strain the poaching milk through a fine-mesh sieve into a bowl and discard the cinnamon stick and lemon peel. You should have about 900 ml milk left.

Whisk the egg yolks, the remaining 100 g sugar, and the cornstarch together until pale and smooth. Slowly pour in about 1 cup of the warm strained milk, whisking constantly, to temper the yolks.

Pour the tempered yolk mixture back into the saucepan with the rest of the milk. Cook over low to medium heat, stirring constantly, for 5 to 7 minutes, until the custard coats the back of a spoon and reaches 170 F / 77 C. Do not let it boil or the yolks will curdle.

Remove from heat and stir in the vanilla extract. Pass the custard through the sieve again if any lumps formed, then cool to room temperature, cover, and chill at least 2 hours.

Divide the chilled custard among 6 small bowls or glasses. Float 1 to 2 meringues on top of each and dust generously with ground cinnamon before serving.