Make sure the ingredients are cold. I put the butter pieces in the freezer for 5-10 minutes, and keep the buttermilk and cream in the fridge up to the last minute.
Have ready a cookie sheet lined with parchment paper, greased or dusted with a little flour.
Preheat oven to 375ºF (190ºC).
In a large bowl, put 2 cups all-purpose flour, 2 ½ teaspoons baking powder (don’t forget it or your scones won’t rise!), 1 teaspoon salt and 3 tablespoons sugar. Stir to mix.
Scatter 4 tablespoons butter, cold and in small pieces, on top and start working it into the flour mixture. You can use a dough cutter. Mix it with the dry ingredients, but be careful not to warm it too much. If you feel it starts to soften, pop the bowl in the fridge for a few minutes, or the freezer, until it firms up again. The butter should have some pieces the size of peas. Lightly beat 1 egg in a small bowl to mix it, so it integrates better.
Make a well in the middle of the dry ingredients, and add the egg, half the buttermilk, and 2 tablespoons whipping or heavy cream.
With a fork or spoon, lightly stir and begin to incorporate the flour. The flour and butter should be wet, but dry spots must be seen. Add the rest of the buttermilk a little at a time. You might end up using all of it or not.
Transfer to a clean surface or counter that is lightly dusted with flour.
Gather it and turn it onto itself a few times. The dough will be floury and messy, but you don’t want to work it too much or make it as smooth as pie dough. After a few turns, it will come together if you take a bit and squeeze it; it should come together and not be too wet or too dry.
Press the whole mixture about 1-inch thick. The outer parts might be dry, don’t worry.
With a round cookie cutter (I use a flower shape sometimes because I like how irregular they bake) cut the scones and put on the prepared pan, leaving 2 inches or so between them.
Repeat with the remaining dough, bringing in the outer dry parts and incorporating them into the dough. Work it as little as possible so the butter stays cold. When all you’re scones are cut, take the baking sheet to the freezer for 5 minutes or the fridge for 15 minutes.
Then bake the cold scones, directly from the refrigerator or freezer, for 20 minutes or so, until puffed, dry, and a bit golden. If you open one slightly, it should be dry inside.
I recommend eating them freshly baked. Keep leftovers in tins and re-warm in a medium oven before eating.