Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
In a large mixing bowl, combine the flour, sugar, baking powder, salt, and poppy seeds.
Add the lemon zest and mix well.
Cut in the cold, cubed butter until the mixture resembles coarse crumbs.
In a separate bowl, whisk together the heavy cream, lemon juice, and vanilla extract.
Pour the wet ingredients into the dry ingredients and mix until just combined.
Turn the dough out onto a floured surface and shape it into a circle about 1 inch thick.
Cut the dough into 8 wedges and place them on the prepared baking sheet.
Bake for 18-20 minutes, or until the scones are golden brown.
Let cool slightly before serving. Enjoy!