Set the oven to 350 degrees, and find a 13 X 9-inch pan.
Make the crust. To work by hand, combine the flour and ½ cup of confectioners’ sugar in a medium work bowl. Chop the butter in bits, then cut it into the dry ingredients with a pastry blender, a couple butter knives or a chopper, (or, if you have nice cold hands, you can quickly rub the butter into the flour with your fingertips). To use a food processor, put the crust ingredients in it, then whir in the cold butter. Regardless of technology selected, the dough will appear crumbly and powdery.
Press the dough evenly into the pan, then bake it until very pale golden, about 20 minutes.
For the filling, whisk the eggs in a medium bowl. Add remaining ingredients and whisk to combine well, then pour the custard onto the baked crust.
Return the pan to the hot oven and bake for an additional 20 to 30 minutes, or until custard is set and very lightly golden.
Allow to cool thoroughly before cutting.