Cut butter into 1/2-inch cubes: halve the stick lengthwise, rotate it 90º and slice lengthwise again, then slice crosswise into 1/2-inch pieces. Place in a bowl and pop in the freezer while you prepare the dry ingredients (you want the butter to stay as cold as possible until you're actually baking the scones).
Combine flour, sugar, baking soda, salt and dried lavender in a food processor. Pulse several times to thoroughly mix everything. Beat egg and 3/4 cup half & half together in a bowl, then stir in the lemon extract. Set aside.
Add cubed butter to dry ingredients in food processor and pulse until the mix resembles a coarse meal, with bits of butter pea-sized or smaller.
Transfer flour mix to a mixing bowl. Check with your hands for errant pieces of butter that are too large and break them up with your fingers.
Stir the lemon zest into the flour mix. Pour egg/half & half/lemon extract mixture over everything and stir to combine. If it happens to not be coming together, add a little more half & half, a tablespoon at a time. But be cautious; the dough can be quite sticky.
With flour-dusted hands, transfer mix onto a lightly floured surface. Working quickly, shape it into an 8-inch disk, about 1 inch thick, slightly mounded in the center. Again, it can be sticky; dust your hands with more flour or even sprinkle a little over the dough as needed.
Don’t skip this step. Place the dough disk on its silicone baking mat on a hotel pan and pop it in the freezer for 20 to 30 minutes. This will make the notoriously sticky dough much easier to cut into wedges and handle.
Using a sharp knife, cut into 8 wedges.
At this point, we highly recommend freezing the scones to bake later. This helps the end product stay more scone-shaped, not spreading out as the fresh dough can. Also, you can bake fewer scones at a time. There’s not suddenly two of you staring down eight scones. And if you wake up on a random Tuesday morning thinking a scone would start the day just right, you’re that much closer. Transfer the individual scones to a parchment- or silicone baking mat-lined hotel tray pan. Cover with waxed paper and freeze for at least two hours. Then store scones in zippered plastic bags; we do them in sets of two.
Do not thaw scones to bake. Preheat oven to 400ºF and place scones on a lined baking sheet. Brush tops with a little half & half, and sprinkle with sugar, if desired. Bake until golden, 18 – 20 minutes, rotating sheet halfway through. Watch closely toward the end so they don’t brown too much.
Transfer baked scones to a wire cooling rack and cool either slightly or completely, depending on your will power.
You can also bake all or some of the scones right now. If you plan to do this, preheat the oven while the disk is still in the freezer and follow the baking instructions above, but check them at 16 minutes to be on the safe side.