1 large navel orange
1 large Cara Cara orange
1 tablespoon unsalted butter, melted
2 tablespoons brown sugar
1 pinch cinnamon
Vanilla yogurt
Mint sprigs, for optional garnish
Preheat oven to broil and position rack on the second from top position.
Cut off ends of each orange, then cut off the rind using a paring knife, making certain that no bitter white pith remains.
Cut each orange crosswise into thirds and place in an oven-proof baking dish.
Combine melted butter with brown sugar, then spread over orange rounds.
Sprinkle with cinnamon.
Place oranges in the oven and broil several minutes until the oranges are hot and begin to form brown spots on the tops.
To serve, arrange oranges in pretty stemmed glassware and drizzle with any cooking juices. Top with a dollop of yogurt and a mint sprig.