Wash the oranges thoroughly and cut off the ends. Score the peel into quarters and remove the peel, avoiding the white pith as much as possible.

Place the orange peels in a saucepan and cover with water. Bring to a boil and simmer for 10 minutes. Drain and repeat this process two more times to reduce bitterness.

In the same saucepan, combine 2 cups of sugar and 2 cups of water. Bring to a boil, stirring until the sugar dissolves.

Add the blanched orange peels to the syrup and simmer for about 45 minutes, or until the peels are translucent and the syrup thickens. Use a candy thermometer to check for a temperature of 230°F (110°C).

Remove the peels from the syrup using a slotted spoon and place them on a baking sheet lined with parchment paper. Allow to cool slightly, then roll in granulated sugar to coat.

Let the coated peels dry at room temperature for at least 24 hours before storing in an airtight container.