Preheat oven to 325°F (160°C). Combine milk, cream, 1/3 cup (75 mL) brown sugar, orange zest and 1 tsp (5 mL) cinnamon in medium saucepan; bring to simmer over medium heat. Meanwhile, in medium bowl, whisk yolks with 1/4 cup (60 mL) brown sugar and salt. Temper this yolk mixture by slowly adding 1/2 cup (125 mL) hot milk mixture from saucepan while whisking quickly. Whisk tempered yolk mixture into the hot milk mixture. Stir in vanilla.
Lined a roasting pan with clean kitchen towel (towel prevents ramekins from sliding). Place 6 (6-oz) ramekins onto towel. Add 1/4 cup (60 mL) blueberries into each ramekin. Pour 1/3 cup (75 mL) custard mixture into each ramekin.
Set roasting pan on middle rack of oven. Carefully pour hot water into the roasting pan to come halfway up sides of ramekins (be careful not to splash water into ramekins). Bake 45 to 50 min. until edges of custards have set but centres still jiggle slightly. Remove roasting pan from oven. Let custards stand in water bath 5 min. Remove ramekins from water bath; cool 30 min. at room temperature. Cover with plastic wrap; chill 2 hr.
To serve, mix remaining brown sugar and cinnamon and sprinkle evenly over each custard. Arrange ramekins on a baking sheet and place under broiler 2 to 3 min. until sugar begins to brown. Let sugar coating cool and harden before serving.
The custard cream (step 1) can be made up to 2 days ahead, covered and kept chilled to bake as required.