Preheat oven to 300°.
Combine milk, dry milk, and salt in a small saucepan over medium heat. Heat to 180° or until tiny bubbles form around the edge (do not boil), stirring occasionally. Remove from heat; stir in orange rind and cinnamon stick. Cover and let steep 10 minutes. Strain milk mixture through a sieve into a bowl; discard solids. Stir in vanilla extract.
Combine 2 tablespoons sugar and egg yolks in a medium bowl; stir well with a whisk to combine.
Gradually add milk mixture to egg mixture, stirring constantly with a whisk. Divide milk mixture evenly between 2 shallow (6-ounce) dishes. Place dishes in a 13 x 9–inch baking pan; add hot water to pan to a depth of 1 inch. Bake at 300° for 40 minutes or until center barely moves when dish is touched. Remove dishes from pan; cool completely on a wire rack. Cover and chill at least 4 hours or overnight.
Sift remaining 2 tablespoons sugar evenly over the top of brûlées. Holding a kitchen blowtorch about 2 inches from the top of each custard, heat the sugar, moving the torch back and forth, until sugar is completely melted and caramelized (about 1 minute). Serve within 1 hour.