Preheat the oven to 180°C / 160°C (fan oven) / 360°F / Gas Mark 4. Put the rhubarb in a pan with the caster sugar and cornflour, toss to coat.

Add half the orange zest and all the juice to the pan with 4 tbsp water. Bring to a simmer; reduce the heat to very low and cook for 10 minutes, swirling the pan occasionally until the rhubarb is completely tender when pierced.

Meanwhile, melt the spread in a pan with the honey and a pinch of salt. Add the granola and stir to completely coat. Tip the rhubarb into a baking dish and spoon over the granola, leaving a border of fruit around the edge. Scatter with the pumpkin seeds then bake for 15-20 minutes until bubbling. Scatter with the remaining zest and optionally serve with vanilla ice cream.