300g/10Β½oz slender young rhubarb, trimmed and cut into roughly 2cm/ΒΎin lengths
1 tsp baking powder
200g/7oz caster sugar, plus 3 tbsp for the topping
200g/7oz ground almonds
200g/7oz self-raising flour
1 tsp vanilla extract or almond extract
200g/7oz softened butter, plus extra for greasing
3 large free-range eggs