Pour the sugar into a large mixing bowl. If you are using the lemon zest, zest the lemons right over the sugar then rub the zest into the sugar with your fingers.

Add the salt, flour and baking powder. Whisk to combine.

Use the largest side of a cheese grater to slice the butter into thin pats. Toss the butter into the flour mixture and rub it in, breaking up the butter bits until they are about kidney bean sized. (Alternatively, slice the butter with a knife and use a pastry cutter to cut it into the flour).

Separately whisk together the buttermilk and vanilla. Pour it into the larger bowl and stir to disperse the liquid into the dry. Use your hands to bring the dough together, folding it over and squeezing it together, until you have a shaggy ball.

Transfer the dough onto a floured surface and flatten into a disk that’s about an inch thick. Slice the dough into quarters and stack them, then press them down to flatten into a disk again (this step develops more flaky layers). Slice the disk in half, then quarters, then eights so you have 8 small scones.

Grease then line a half cookie sheet with parchment paper. Arrange the scones so they are fairly close together, no more than half an inch between them (this helps them rise higher). Set in the freezer, to chill for about 20 minutes.

Preheat the oven to 400 F. If you will not be glazing the scones, you can brush the tops with cream/milk and sprinkle coarse sugar on top. Bake the scones until deeply golden all over and the centers no longer look wet; about 20-25 minutes. (p.s. Sometimes they rise and collapse onto their neighbors, that’s those lovely flaky layers!)

If you are glazing, wait until the scones are completely cool. Whisk together the glaze ingredients (add more milk/cream to thin it out, more sugar to make it thicker) and spoon over the baked scones.