Preheat the oven to 180°C (355°F) bake function.
Line a roasting tray with nonstick baking paper.
Arrange the rhubarb in the prepared tray.
Scatter over the sugar and roast for 10-15 minutes, until the rhubarb is tender, but holds its shape.
While the rhubarb roasts, make the ginger crumbs and custard.
Crumble the soft ginger cookies.
Place in the roasting tray, sprinkle the brown sugar, ginger and cinnamon.
Bake for 10 to 12 minutes, until golden (turn once while cooking).
Make the custard. In a large microwave safe bowl, dissolve the custard powder and sugar in 60ml (¼ cup) of low FODMAP milk.
Then whisk through the rest of the milk and vanilla essence.
Place in the microwave and heat for 2 minutes, whisk and heat for another 2 minutes.
Whisk again and heat in 1 minute bursts until thick (the custard will continue to thicken as it cools).
Serve the roast rhubarb with the custard and top with ginger crumbs.
