Preheat the oven to 160°C.
Heat 1cm rhubarb pieces with sugar and water until a syrup forms.
Place more 1cm rhubarb pieces on a baking tray and sprinkle with sugar.
Glaze rhubarb strips with syrup and bake for 7 minutes until tender.
Beat egg yolks with sugar and boil the milk and cream together.
Whisk the hot cream into the yolk mixture over simmering water.
Add cornflour and vanilla seeds then stir until the custard thickens.
Layer rhubarb syrup and custard in glasses and chill overnight.
Preheat the oven to 180°C and line a tray.
Rub flour, butter, sugar, and almonds together into breadcrumbs.
Bake crumble for 20 minutes until golden and let cool.
Top chilled custard with baked rhubarb, glazed strips, and crumble.