I use the Ottolenghi recipe, same as post below
250g Ground Almonds
3/4 tbsp of booze, cognac, rum etc
Cream the butter with an electric whisk, when light and creamy whisk in sugar, then almonds, eggs then flour until all mixed well.
For the plums use about 15-20, cut them in half and then cut the halves into 3 wedges. Put in a bowl with a good sprinkling of caster sugar and leave for 10 mins.
Spoon the almond paste into the tart case and then push the plums in making a pretty pattern.
Bake in the oven for about 30-40 mins so that the mixture is golden, set and not wobbly.
Leave to cool or serve warm, it looks amazing finished with a glaze so heat up a few tbsps of jam until runny and lightly paint over the tart with a pastry brush. Serve with creme fraiche.