- Place the butter in the freezer overnight in advance.
- Place the water in the freezer an hour before cooking.
- Sift the flour, add salt.
- On a coarse grater, quickly grate the butter, periodically mixing it with flour.
- Pour in very cold water, and mix quickly. *Kneading until homogeneous is not necessary. Just grab the pastry into a ball. Put in a bag and refrigerate for half an hour.
- Divide the dough into 10 even pieces.
- Roll out on parchment into a thin layer, cut out a circle of the right size, sprinkle with powdered sugar and bake together with the trimmings in a preheated oven at 464F (240C) in the convention mode for 6-7 minutes.
- Place on wire rack and cool completely.
*Cold dough is easier and faster to roll out without extra flour, so keep the rest pieces in the freezer while rolling out a copuple of them.
- Mix the yolks with sugar and starch, add hot milk. Cook until thickened. Remove from the heat and add vanilla paste.
Cover with cling film and cool completely.
- Beat the butter until white and fluffy.
- Add custard and condensed milk alternating spoon by spoon. Whisk until smooth.
- Cook the blueberries with sugar until the sugar dissolves.
- Mix the starch with water. Pour this mixture into the berries in a thin stream. Whisk quickly.
- Cook for a minute. Cool in the fridge.
- Grease each pastry layer with custard.
- Alternate these layers, adding some confit over several custard layers.
- Grease the sides and the top of the cake with custard and sprinkle with pastry crumbs.
- Let the cake stabilize in the fridge.