Preheat the oven to 375°F. Lightly grease a 9" x 5" loaf pan., In a large bowl, whisk together the pastry blend or flour, baking powder, baking soda, salt, sugar, currants, and caraway seeds., In a separate bowl, or in a measuring cup, whisk together the egg and buttermilk (or milk and yogurt)., Quickly and gently stir the wet ingredients into the dry ingredients., Stir in the melted butter., Spoon the batter into the prepared pan. Draw your finger around the edge of the pan to create a "moat." Drizzle the bread with the 1 tablespoon of milk; the moat will help prevent the milk from running down the sides of the loaf. Sprinkle with the coarse sugar., Bake the bread for 50 minutes to 1 hour, or until a cake tester inserted into the center comes out clean; the interior of the bread will measure 200°F to 210° on an instant-read thermometer., Remove the bread from the oven, loosen its edges, and after 5 minutes turn it out onto a rack to cool. Cool completely before slicing. Wrap airtight and store at room temperature.