For the Scones:

1. First, dice up your butter into small pieces. Place on a small plate or in a small bowl and put it in the freezer while you prepare the rest of the ingredients. Ensuring your butter is icy cold will yield the best texture and taste for the scones.
2. Preheat the oven to 400°F and line a large baking sheet with parchment paper.
3. In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and poppyseeds.
4. Using a pastry blender, fork, or your hands, work the cold cubed butter into the flour mixture until it resembles a coarse meal. A few larger chunks of butter are fine.
5. Pour the heavy cream, lemon zest, lemon juice, and vanilla into the dry mixture and stir until everything just comes together. Try not to overmix.
6. Transfer the dough to a lightly floured surface and gently form the dough into a large disc, roughly one inch high and 8-10 inches in diameter.
7. Use a sharp knife to cut the scones into 8 triangles. Place the cut scones onto the prepared baking sheet.
8. Place the baking sheet with the scones into a freezer for 10-15 minutes, just to ensure that the butter is super cold. This will allow the scones to puff up and get really flaky in the oven.
9. Remove the scones from the fridge/freezer and brush the tops of the scones with a little heavy cream. Sprinkle turbinado sugar all over the tops.
10. Bake for 18-22 minutes or until the scones are golden brown around the edges, lightly golden on the tops, and puffed. 
11. Cool on the baking sheet for a few minutes and then transfer to a cooling rack to finish cooling.

For the Glaze:

Whisk together the sugar and lemon juice in a small bowl until completely smooth. Add lemon juice and/or more sugar until the glaze is of a drizzling consistency.

To Serve:

1. Drizzle the glaze lightly over the cooled scones and sprinkle with additional poppyseeds.
2. Allow to set for a few minutes and then serve.