1. Preheat Oven:

• Preheat oven to 375°F (190°C).

2. Make the Filling:

• In a medium bowl, toss the sliced rhubarb and quartered strawberries with the sugar, cornstarch, tapioca, orange juice, and orange zest.
• Let the mixture stand for 15 minutes, stirring every 5 minutes. This allows the fruit to release some of its juices and the thickeners to start working.

3. Make the Dough:

• In a large bowl, whisk together the flour, brown sugar, baking powder, and salt.
• With a pastry blender or a fork, cut the chilled, diced butter into the dry ingredients until the mixture is incorporated and crumbly. The butter pieces should be about the size of small peas.
• Drizzle the milk evenly over the top of the mixture.
• Stir together just until evenly moistened. Do not over-mix. The dough will be thick.

4. Assemble the Cobbler:

• Transfer the strawberry rhubarb filling to a deep baking dish (approximately 9×11 inches, or a similar size with tall sides).
• Using a spoon, drop the dough onto the top of the strawberry rhubarb filling, dividing it evenly into 8 dough mounds.
• Sprinkle the 2 tablespoons of sugar evenly over the dough mounds.

5. Bake the Cobbler:

• Bake, uncovered, for about 40 minutes, or until the biscuits are browned and the filling juices are thickened and bubbling nicely.

6. Cool and Serve:

• Remove the cobbler from the oven and place it on a cooling rack.
• Let cool for about 30 minutes before serving.
• Serve warm with a scoop of vanilla bean ice cream, a dollop of whipped cream, or a splash of cream.