6. In a mixing bowl, cream together the softened butter and white sugar until light and fluffy. This should take 5-6 minutes. Gradually add the vanilla extract and beaten eggs one at a time, mixing well after each addition. It is likely to curdle but it will come together at a later stage, so don’t panic!
7. In a separate bowl, sift together the plain flour, salt and baking powder. Gradually add this to the butter-sugar-egg mixture, folding until just combined.
8. Pour the cake batter into the prepared cake pan, spreading it evenly.
9. Next, spread the pastry cream over the entire cake batter, getting it right to the edges.
10. Arrange the rhubarb pieces on top of the pastry cream.
11. Bake for 1 hour or until the cake is golden brown and a skewer inserted into the centre comes out clean.
12. Remove the cake from the oven and let it cool in the pan for a few minutes, before transferring to a wire rack to cool for another ten minutes.
13. Serve the cake warm or at room temperature with a handful of flaked almonds, a dusting of icing sugar and scoop of vanilla ice cream.