Preheat your oven to 425ºF and line a baking sheet with parchment paper.
In a large bowl, add the granulated sugar and lemon zest and mix with your hands to release the essence of the zest and incorporate it into the sugar. Add the flour, salt and baking soda and whisk until combined.
In a medium bowl combine the 2/3 cup half and half, vanilla extract and 1 tablespoon lemon juice and pour into the bowl with the dry ingredients. Stir with a wooden spoon or a spatula until just combined. Add one tablespoon at a time of half and half if you have dry bits remaining in the bowl. Transfer onto a lightly-floured surface and form into a disk. Cut into eight wedges and transfer to the baking sheet. If you decide to use the turbinado sugar, brush the tops of the wedges with a little half and half and sprinkle the turbinado sugar on top. I like to use it for added texture.
Bake for 18-20 minutes, rotating the pan halfway through, or until the scones are lightly golden. Remove from oven and transfer to a cooking rack. Allow to cool for a few minutes before adding the lemon glaze if you decide to use it.
Combine the powdered sugar and two tablespoons lemon juice in a small bowl and stir until smooth. Drizzle on top of the slightly-cooled scones or brush with a silicon brush.
Sugar: Even at 1/2 cup these scones aren't very sweet but if you add the glaze you can reduce the amount to 1/3 cup.
Half and Half: Start with 2/3 cup and add one tablespoon at a time until most of the dry bits of flour have been incorporated into the dough.