Pre-heat your oven to 180C Fan/Gas Mark 6
To make the pastry, use your fingers to rub the butter into the plain flour and caster sugar until it resembles breadcrumbs. You can also make it in a food processor
Add the milk and form a dough, being careful not to over work it or knead it
Roll out the pastry on a surface or silicone mat dusted with flour. Line a 9 inch loose bottomed tart tin with the pastry and trim off any overhang
Use a fork to prick the bottom of the pastry then chill it in the fridge for 30 minutes
Scrunch up some baking paper and line the pastry, then add baking beans or some rice on top. Bake it for 15 minutes
Take the pastry out of the oven and remove the baking beans and paper. Bake the pastry again for 10 minutes on the same temperature, or until golden and it no longer looks raw on the base
Reduce the oven temperature to 160C Fan/Gas Mark 4
To make the frangipane mix together the butter and the caster sugar, ideally using an electric mixer. Then add the eggs one at a time and mix in, then mix in the vanilla extract and almond extract
Then mix in the ground almonds and plain flour
Spread the jam on the bottom of the pastry case
Pipe the frangipane over the top of the jam and avoid it mixing with the jam, then smooth it out on top. Sprinkle over the flaked almonds
Bake the tart for 40 minutes or until risen and golden all over. The frangipane filling should be more like a set custard rather than a fluffy sponge
When the tart is cool, mix the icing sugar with enough water to get a thick, but pipeable paste. Drizzle or pipe over the tart
Store leftovers in an airtight container for up to 3 days