Line the pastry with a scrunched up piece of baking paper, then fill with baking beans or uncooked rice. Blind bake for 15 minutes. Remove the beans and paper and bake for another 5 minutes until the pastry looks dry and lightly golden. Brush with the egg white while still hot, and allow to cool. To make the frangipane, beat the butter, sugar and almond extract together. Add one egg, and beat again. Add a spoonful of ground almonds to help the egg bind, then add the remaining egg with another tbsp of almonds and beat until incorporated. Mix in the remaining ground almonds and flour. If the mix is a little stiff, add the milk and whisk again.