Steps
- Mix 300g of self-rising flour, 50g of custard powder, ¼ teaspoon of fine salt, 1 teaspoon of baking powder, and 50g of superfine sugar. Rub in 95g of cold cubed unsalted butter until finely crumbed.
- Gradually mix in 150ml of whole milk to make a smooth dough, adding a little more if needed. Roll out on a floured surface to ¾in / 2cm thick; cover on a parchment-lined baking sheet and chill for 30 minutes.
- Combine 250g of chopped fresh rhubarb, 100g of superfine sugar, the zest of 1 lemon, ½ teaspoon of vanilla bean paste, and 2 tablespoons of water in a saucepan.
- Simmer over medium heat for 10-15 minutes. Stir occasionally, until the rhubarb collapses and the compote thickens; cool completely.
- Preheat the oven to 425°F / 220°C. Cut out 2¾in / 7cm rounds without twisting, rerolling the scraps; space ¾in / 2cm apart on a parchment-lined baking sheet.
- Brush the tops with 1 beaten egg, keeping the glaze off the sides. Bake for 10-12 minutes, until golden; cool completely and spoon the compote onto the split scones.