For the dough, mix flour, salt and 100 g sugar. Add butter in flakes and rub the whole thing between your hands until you get a sandy dough. Make a depression in the dough, whisk 1 egg, add it and quickly work it into a smooth dough. Wrap in foil and chill for about 1 hour
Dissolve soluble coffee in 1 tablespoon of hot water. Roll out the dough between two layers of baking paper and cut out 8 circles (approx. 14 cm Ø). Grease tartlet moulds (approx. 12 cm) and dust with flour. Line with the dough, prick several times with a fork and chill for about 30 minutes
Line tartlets with baking paper and fill with dry peas for blind baking. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 10 minutes. Whisk 3 eggs, 75 g sugar, coffee and 1 tsp. cocoa. Stir in cream
Take out the tartlets, remove the baking paper and dried peas. Pour coffee cream on the tartlet bottoms and bake at the same temperature for 20-25 minutes. Leave to cool and dust the rest of the cocoa over the tartelettes before serving
waiting time approx. 1 1/2 hours