Place the flour, almond meal, icing sugar and butter in a food processor and process until mixture resembles fine breadcrumbs. Add the egg yolk and water and process until dough just comes together. Shape into a log and cover with plastic wrap. Place in the fridge for 30 mins to rest.
Roll out the pastry on a lightly floured surface to a 3mm-thick rectangle. Line the base and sides of an 11cm x 34cm rectangular tart pan, with removable base, with the pastry. Use a small knife to trim the edges. Place in the fridge for a further 30 mins to rest.
Preheat oven to 200°C. Line the pastry case with baking paper and fill with pastry weights or rice. Bake for 10 mins. Remove the paper and weights or rice and bake for a further 10 mins or until golden. Remove from oven. Reduce oven temperature to 180°C.
To make the frangipane filling, use an electric mixer to beat the butter and sugar in a bowl until pale and creamy. Add the egg and beat to combine. Add the almond meal and flour and stir with a wooden spoon to combine.
Spread ⅓ cup (110g) jam evenly over the base of the pastry case. Spread the frangipane evenly over the jam. Arrange rhubarb slices on top. Sprinkle with caster sugar. Bake for 30 mins or until the frangipane is set. Set aside to cool.
Melt remaining jam in a saucepan over low heat. Strain through a fine sieve. Brush the hot jam evenly over the rhubarb. Cut into slices to serve.