Direction :

1. Preheat the oven to 400ºF. Line a rimmed baking sheet with parchment paper.
2. If your currants are very dry, place them in a small bowl, cover them with warm water, and set aside for about 10 minutes until the currants are plumped. Drain well. If your currants are moist out of the container, you can skip this step — I’ve been using Sun-Maid Zante Currants, which are very moist, so I’ve been skipping this step. 
3. In a large bowl, place the sugar. Zest the lemon into the sugar, then use your hands to rub the zest into the sugar — this releases the oils in the zest and heightens the lemon flavor in the finished scones. 
4. Add the flour, baking powder, baking soda, and salt, and whisk to combine. Add the currants and whisk again. 
5. Grate the butter using a box grater, then scatter it over the dry ingredients. Toss gently with your hands to disperse the butter evenly throughout the dry ingredients. Alternatively, cut the butter into 1/2 slices, then use a pastry blender or the back of a fork to cut the butter into the dry ingredients. 
6. Add the buttermilk, starting with 3/4 cup (180 grams) and mix gently with a wooden spoon or spatula until the dough holds together. If the mixture seems dry, add more buttermilk by the tablespoon until the dough comes together (I consistently need 3/4 cup + 1-2 tablespoons of buttermilk total but I have used a full cup of buttermilk with success, too). If necessary, knead the dough gently with your hands to help it come together.
7. Dust your work surface with flour and turn the dough out onto it. Using your hands, pat the dough into roughly a 7-inch circle about 1½ inches thick. (Note: At this point, you can transfer the scone dough to the fridge in an airtight bag until you are ready to bake (for as long as 24 hours)). Brush the top with melted butter. Sprinkle with sugar. Cut the circle into 6 to 8 triangles, then transfer them to the prepared sheet pan. If time permits,  chill the scones for 20 minutes.  You also can freeze the scones at this point — see notes above.
8. I like to place the pan on another rimmed baking sheet because often the bottom of my scones burn, but if you don’t have issues with your baking sheets, just use one sheet. Transfer to the oven and bake until the tops of the scones are lightly browned, about 20 minutes.
9. Remove from the oven, let cool briefly, then serve with butter, lemon cream, clotted cream, jam or nothing at all.