Heat the oven to 200C/180C fan/gas 6. Put all the ingredients for the rhubarb in a roasting tin, toss to coat, ensure the rhubarb is in a single layer, cover and roast for 12-14 mins until the rhubarb is soft but still holding its shape. Spoon into a bowl, then pour the roasting juices into a pan and simmer over a medium-high heat for 3-4 mins until syrupy.

Whisk the flour, baking powder, sugar and custard powder together in a bowl. Add the milk and eggs, and whisk to a smooth batter. This is easier using a stick blender.

Melt a small knob of the butter in a non-stick frying pan over a medium heat, carefully wiping it around the base using kitchen paper. Spoon in some batter to make 8cm circles, and cook for 1-2 mins until bubbles start to appear on the surface. Flip and cook for another 1-2 mins until golden and cooked through. Repeat with the remaining pancake batter and butter.

Stack the pancakes up with the custard and poached rhubarb between each layer. Spoon over the rhubarb syrup to serve.