Finely grated zest and juice of 3 large lemons
1 cup caster sugar
200g unsalted butter
½ cup brown sugar
½ cup plain flour
½ tsp ground nutmeg
2 cups frozen raspberries
Preheat oven to 180°C. Line an oven tray with baking paper. Combine eggs, lemon zest and juice, ¾ cup of the caster sugar and 125g of the butter in a heatproof bowl over a saucepan of barely simmering water. Cook, stirring, for 10 minutes or until thickened, then set aside to cool completely.
Meanwhile, combine brown sugar, flour, nutmeg and remaining butter in a medium bowl and rub with fingertips until a crumb forms. Scatter over prepared tray. Bake for 15 minutes or until crisp. Set aside to cool. Break up crumbs.
Put raspberries and remaining caster sugar in a pan over a medium heat. Cook for 5 minutes or until sugar has just dissolved. Set aside to cool.
Layer lemon butter, crumb and sauce in serving glasses, finishing with crumb. Serve.