Roast the rhubarb by washing it, cutting into small pieces (5-6 cm in length) and sprinkling over 50 g caster sugar, then roasting for 15 minutes in a foil-covered dish. Then remove the foil and roast for 5 minutes more. Leave to cool.
1 pack of rhubarb
Cream together the butter and sugar until light and fluffy.
150 g unsalted butter, 190 g golden caster sugar
Add the vanilla bean paste and then the eggs, one by one.
1 tsp vanilla bean paste, 3 medium eggs
Fold in some of the flour, then add some of the buttermilk. Add each in stages and mix in between until all fully added.
225 g self-raising flour, 120 ml buttermilk
Place half of the cake mixture in a deep 8-inch/20 cm springform cake tin sprayed with cake release spray.
Place some pieces of the drained roasted rhubarb on top, then add the rest of the cake mixture on top of it.
Smooth the top then place more of the drained roasted rhubarb on top (you may not want to use it all, I had some left over).
Bake for 50-55 minutes at 180℃ / 350℉ (preheated oven), or until the cake is golden brown and fully cooked in the centre - check using a cake tester.
Enjoy!