Slice the oranges into thin ¼-inch rounds using a sharp knife or a mandoline for consistent thickness.

In a large skillet or saucepan, combine 3 cups of granulated sugar and 3 cups of water over medium-high heat. Stir gently until the sugar completely dissolves.

Reduce the heat to maintain a gentle simmer and carefully add the orange slices in a single layer. Simmer the oranges for 45–60 minutes.

Using tongs, remove the candied orange slices from the syrup and place them in a single layer on a wire rack to dry.

For an added touch, consider rolling the dried slices in granulated sugar or dipping them in melted chocolate.