Preheat your oven to 350°F (175°C). Place a rack in the center of the oven.

Crack 4 large eggs into a large mixing bowl.

Whisk the eggs gently until the yolks and whites are completely combined. Don't whip too aggressively—you don't want too many bubbles in the custard.

Add ½ cup granulated sugar to the eggs.

Whisk until the sugar is mostly dissolved and the mixture looks smooth.

Slowly pour in 2 cups of whole milk while continuing to whisk.

Add 1 teaspoon vanilla extract and a tiny pinch of salt if using.

Mix everything until you have a smooth, pale yellow custard mixture.

Use small rectangular aluminum baking trays, similar to the ones shown in the picture.

Lightly grease the inside of the trays with a little butter or cooking spray.

Place the trays on a sturdy baking sheet so they're easier and safer to move.

Slowly divide the custard mixture between the two trays.

Don't fill them completely to the top—leave a little room because the custard will gently puff while baking.

If you see large bubbles on the surface, gently tap the baking sheet against the counter a couple of times.

Lightly sprinkle ground cinnamon over the top.

You don't need much—just enough to create that beautiful classic appearance shown in the reference.

Carefully place the trays into the preheated 350°F oven.

Bake for approximately 35–40 minutes, depending on the depth and size of your baking dishes.

The edges should become golden brown, while the center should look set but still have a slight gentle jiggle.

Don't overbake, or the custard can become rubbery.

Remove the trays from the oven and place them on a heat-safe surface.

Let them rest for around 10–15 minutes.