In a large bowl that you can comfortably get your hands in, place the flour and salt. Fluff with a fork or your clean hands to mix.

Add the cold butter, and smoosh and pinch it into the flour with your fingertips, or cut it in with a pastry cutter. The pieces of fat should be no larger than pea size with flakes the size of oats.

In a small bowl, mix together the water, egg yolk, and white vinegar with a fork. Pour over the flour and fat mixture, and fluff with a fork or fingers to mix in.

Bring the dough together and knead it three or four times with the heel of your hand. Pat it out into a flat rectangle, wrap in plastic, and refrigerate for 20 to 30 minutes.

On a well-floured surface, roll out the dough to a rectangle about 12 by 18 inches (30 by 46 cm) and ¼ inch (6 mm) thick. As you roll out the dough, be sure that it isn’t sticking and you can move it on the surface. Add a bit more flour if needed.

Cut the dough into 4-inch (10 cm) circles. Gather the scrap dough together lightly and roll out again and cut until you have 12 circles.

Place a circle of dough in each of the buttered cups. Use your fingers to gently smooth it along the sides. It is okay if there are a few folds in the dough.

Place the dough-filled muffin tin in the fridge while you go on to make the filling.

Preheat the oven to 450°F (230°C).

In a medium bowl, add the brown sugar, salt, and softened butter. With an electric hand mixer, mix on low until the butter and sugar are well combined.

In a small bowl, mix the egg and vanilla together with a fork. Add to the butter and sugar mixture and, using a big spoon, mix until combined.

Stir in the raisins.

Fill each tart shell with 1 scant tablespoon filling.

Bake for about 15 minutes.

When the tin comes out of the oven, run the blade of a knife around the edge of the tarts so they won’t stick. Let cool and then remove from the muffin tin.