1 3/4 cups all-purpose flour
4 teaspoons baking powder
5 tablespoons unsalted butter
5 tablespoons white sugar
2/3 cup whole milk
1/2 cup currants
1 egg yolk, beaten
1. Preheat oven to 400 degrees F (200 degrees C). Lightly grease a baking sheet or line with baking parchment.
2. Sift flour and baking powder into a medium bowl. Rub butter and sugar into flour to form a fine crumble. Make a well in center, and add milk and currants. Knead gently together, being careful not to over mix. Dough will be sticky.
3. On a generously floured surface, roll out dough to 3/4 inch thickness. Stamp out 2 1/2 inch rounds with a plain pastry cutter. Transfer to prepared pan, and brush tops with egg yolk. Allow to stand for 15 minutes.
4. Bake in preheated oven until risen and lightly golden on top, 12 to 15 minutes. Remove to a rack to cool.