Thoroughly clean the oranges using a vegetable brush under running water.
Slice a tiny portion off each orange's top and bottom, then make 4 vertical cuts down the peel to the pith without cutting into the fruit.
Peel off each section carefully and cut the peel into strips about 1/4-inch wide.
Place the orange peel strips in a pot, cover with about an inch of water; bring to a boil, drain, and repeat this once more.
Return the peels to the pot; add 2 cups water, 1 cup sugar, and the vanilla bean if using. Bring to a boil, then lower heat to a simmer and cook uncovered for 30 to 35 minutes until the peels become translucent and the syrup thickens.
Turn off the heat and allow the peels to sit in the remaining syrup for 5 minutes to cool.
Using tongs, transfer the peels to a drying rack over parchment paper and leave them to dry for at least 8 hours, ideally 24.
Once dry, toss the peels in extra granulated sugar. If desired, dip them in melted chocolate and let them cool completely.
Enjoy the candied orange peels right away or store them in an airtight container refrigerated.
