2) Meanwhile, to make the jam, chop one peach (with the skin - this gives it a beautiful pink colour) into small pieces and place in a saucepan with the sugar. Do not add any water. Cook on a medium heat until thickened (about 20 minutes).
3) To test if the jam is done, place a plate in the freezer for 10 minutes, remove and put a teaspoon of jam on it. Allow to rest for 2 minutes and push the mixture back with your finger. If it wrinkles, it's done. Set aside to cool.
4) Preheat the oven to 180C/Gas 4.
5) Remove the pastry dough from the fridge and knead briefly. Flour a large work surface and the top of the dough. Roll the dough until 1/2cm thick and fold over the rolling pin to cover an individual tartlet tin (approximately 12.5cm wide). Use your fingers to fit the pastry into the case and trim the edges, leaving an extra 1cm around the top. Repeat for the rest of the cases.
6) Using a fork, prick plenty of small holes into the bottom and sides of each case. Cover each with greaseproof paper and fill with baking beans. Place on a baking tray and bake for 10-12 minutes.
7) Remove the baking beans and greaseproof paper, trim the edges of the cases again and bake for a further 8-10 minutes or until golden. Remove from the oven and allow to cool.
8) To make the cake filling layer, mix together all the dry ingredients. Whisk the milk, apple cider vinegar and almond essence until slightly thickened. Mix the wet ingredients with the dry, and whisk gently until smooth.
9) Once the tart shells have cooled, add a thin layer of jam and fill the rest with cake mix until just below the top of the tart case. Arrange fresh peach slices on top and repeat for the remaining tarts. Bake again for 20-25 minutes or until golden. If you find the tarts are overbrowning quickly, turn the temperature down or cover with foil and continue baking.
10) Whip together the ingredients for the Cardamom mascarpone cream and serve with the hot or cooled tarts.
11) If you have any leftover jam, dilute it with some water and brush over the top for a glazed effect. Alternatively, dust with icing sugar for a classic look.