Use your fingers to lightly blend the ingredients to a mealy stage.
By hand, lightly whisk together the water and milk powder, then add the eggs, sugar and salt.
Add to the flour mixture all at once. Use your fingers to mix for a short time, until the dough is just slightly developed.
If adding currants, do so at this stage, mixing only long enough to incorporate.
Transfer dough to a sheet of parchment paper and work the dough by folding and pressing gently all sides for about 1 minute, until all ingredients are fully incorporated. The dough should still be flaky.
Lightly flour a rolling pin and roll the dough out to approximately 1.5 cm thickness. Cut into desired shapes and sizes.
Once cut, turn upside down onto lined baking sheet. Egg wash and sprinkle with coarse sugar and bake for 15 minutes, or until tops are golden brown and done.