Start with the pastry. Make sure all the components are very cold as this will result in a crumbly pastry. In a Magimix, Kitchen Aid or bowl, rub the flour and butter together to form coarse breadcrumbs. Add in the sugar and mix gently. Slowly incorporate the egg and yolk, adding a little bit at a time to form a dough. Be patient, as I am always surprised at how easily the dough forms with very little liquid and you might not need all of it. Make sure you have a smooth dough and roll into a flat ball. Wrap and rest in the fridge for at least 30 minutes.
Remove from the fridge and, when the dough is pliable, (don't try to do this stage if the dough is too cold), roll out on a floured surface into a big circle 4cm/1½in larger than the base of a 28cm/11in tart tin that has a removable base. The easiest way to do this is by drawing around the base. The dough should be 3mm/1/8in thick. If you have too much pastry, set the excess to one side for another use.
Line the tart tin with the pastry, pressing in gently to make sure that the pastry hangs slightly over the top of the tin. Rest in the fridge for at least 30 minutes. Preheat the oven to 140°C fan/325°F/gas mark 3. While the pastry is resting, make the frangipane. Cream the butter and caster sugar together until super, super light and fluffy. If the butter is soft, this should take about 5 minutes. Slowly add in the eggs, whisking briskly to prevent the mixture from splitting. If it begins to split, whisk in a small amount of flour until the mixture comes back together. Gently fold in the almonds and the plain flour. Don't overmix. Place in the fridge until ready to use.
Take the tin out of the fridge, line the pastry case with greaseproof paper and then baking beans. Bake for 30 minutes - you want the pastry to cook but not become too browned. Remove the baking beans and greaseproof paper. If the base is still a bit undercooked place back in the oven for 5 more minutes.
Now spoon in the frangipane (you might not need all of it) and place in the oven for 5 minutes to soften the frangipane. Remove from the oven and smooth the frangipane so that it is even and has spread out to the edges. At this stage you might need to add a bit more.
Top evenly with cherries, with stones removed.
Place on a baking tray as the frangipane might overflow slightly and put in the oven.
Cook for 30 minutes. Turn up the heat to 160°C fan/350°F/gas mark 4 and cook for another 15 minutes to firm up the tart and brown the top a little. You want almost no wobble when you remove it from the oven.
Let cool for 10 minutes, then remove the tart from its tin. Leave to cool on a wire rack for another 10 minutes and serve with a blob of crème fraîche.