Line two baking sheets with parchment paper or silicone baking mats.
Once doubled in size, lightly sprinkle the dough with flour and punch out the air from the dough.
Weigh the dough and then divide the number by 10. Use a bench scraper or your hands to divide the dough into 10 equal portions.
Shape each portion into a ball by gently flattening it out, and then tucking the edges under to create a taught surface.
Roll the ball of dough in a clockwise direction under the palm of your hand on a clean work surface.
Starting with the first portion that you shaped, roll the ball of dough out on a lightly floured surface to 3" in diameter.
Continue rolling out each portion of dough and then place 5, evenly spaced, onto the lined baking sheets.
Lay a kitchen towel over top of both baking sheets and leave them to proof for about 15 minutes, somewhere warm.
They don't need to double in size, just become a little puffy.
When ready, press a well into the center of each portion of dough that is about 2" in diameter so that a 1/2" border is created around each pastry.
This is super important because it will help the filling stay inside.
Use a 1/4 cup ladle or a 1/4 cup measure to scoop the custard filling into the well in each pastry.
Optionally add a few red currants (about 1 stalk) or raspberries into the custard center.
Place the two baking sheets in the preheated oven and bake for 12 minutes.
Rotate and swap the baking sheets and bake for another 10-12 minutes. Once baked remove the baking sheets from the oven and place on wire racks to cool.
Melt a tablespoon of butter in a small bowl in the microwave and use a pastry brush to brush the butter onto just the dough border of the pastry, avoiding the custard center.
Leave to cool for about 15 minutes, then dust with powdered sugar when you are ready to enjoy.