In a large mixing bowl, combine flour, salt, and 1 tablespoon of sugar. Add the chilled butter and break it up with your hands until mixture resembles coarse crumbs. Add 2 tablespoons ice water. Once the dough is workable, turn out onto a lightly floured surface and form mixture into a ball. Wrap and refrigerate for at least 20 minutes.
While the dough is resting, make the filling. Dissolve ½ cup sugar into 1 cup of hot water, then let cool to room temperature. Whisk eggs and evaporated milk together, then incorporate sugar water and vanilla. Strain through a fine mesh strainer, then refrigerate covered until you’re ready to bake.
Preheat oven to 400˚F/200˚C. Roll out dough and cut circles to fit your tins. If you don’t have egg tart tins, you can use muffin tins. Press the dough into the tins. Press the dough a little higher than the edge of the mould. Using a fork, poke the bottoms of the dough for even cooking.
Pour the custard into the tart shells until about 75% full. Transfer to a pan and bake for 15 minutes. Reduce the temperature to 350˚F/180˚C and bake another 10-12 minutes, until the filling is set.