Using a paring knife make a slit down the middle of the vanilla bean, keeping the ends intact. Peel 4 strips of the orange, being careful not to cut any of the white pith, which is bitter.
Bring the milk, cream, vanilla, orange rind and cinnamon (if using) to a boil over low heat.
Remove from the heat and let it cool down.
Strain the milk and cream mixture to remove the vanilla bean, orange peel strips and cinnamon stick and discard them.
Using a whisk, mix the egg yolks and sugar until you obtain a thick creamy mixture.
Dissolve the cornstarch in 1 cup of the cooled milk mixture, the stir it back into the remaining milk mixture.
Mix the milk in with the egg yolks and sugar, place it in a double boiler (See Note 1) over medium heat, and stir constantly until the cream thickens, do not let it boil.
Cool the cream and pour into the ramekins or cazuelas. Place them on a tray or baking sheet, cover with plastic wrap and chill overnight in refrigerator.
When ready to serve sprinkle 1 tablespoon of the turbinado sugar over each ramekin or cazuela. Heat a Catalana iron on an electric stove top burner or has flame, then press it against the sugar until burns. Repeat for remaining custards. You can also use a kitchen torch or place them under an oven broiler. Serve immediately.
A double boiler is a pan that is constructed in two parts. The lower half of a double boiler contains the boiling water, the upper half holds the food being cooked and fits above the water. The upper part of the double boiler which holds the food does not touch the water, cooking occurs because of the steam heat generated by the boiling water. (source: Grammarist.com)