PREPARATION

Gather all the ingredients and utensils to be used.

PREPARE THE ORANGE OR GRAPEFRUIT PEEL

Remove the outer peel (green or yellow) and keep the white layer between the peel and the pulp.
You can grate it using the fine side of a grater or use a vegetable peeler to remove only the outer layer.
Keep only the white part of the peel.
Cut into 4 slices or strips and remove the pulp.
Place the strips in a container with water and salt.
Let rest for at least 2 hours (preferably overnight).
Remove the strips from the salted water, rinse them, and boil them in a pot of water over high heat until tender.
Remove from the heat, change the water, and cool.
Squeeze the peels by hand to remove excess water and bitterness.
Repeat the process several times (boil, cool, and squeeze) until the bitter taste disappears.
Drain well. This same method can be used for orange, grapefruit, or mandarin peels.

PREPARE THE SYRUP

In a large pot, add the sugar and water. Boil over high heat until you get a clear syrup.
Add the orange strips. When it starts boiling again, lower the heat and cook uncovered over low heat for 2 hours.
Turn off the heat, cover with a cloth napkin, and let rest for 2 hours.
Return to high heat, add cinnamon and vanilla, and boil for about 15 more minutes until the syrup thickens and the peels look translucent.
Let cool.
Transfer to glass jars and refrigerate to preserve better.