01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, whisk together flour, sugar, poppy seeds, baking powder, and salt.
03 - Add cold, cubed butter to the dry ingredients. Using a pastry cutter or fingertips, cut in butter until mixture resembles coarse crumbs.
04 - In a separate bowl, whisk together cream, egg, lemon zest, lemon juice, and vanilla extract.
05 - Pour wet ingredients into dry ingredients. Stir gently with a fork until just combined. Do not overmix.
06 - Turn dough onto lightly floured surface. Pat into 1-inch thick circle about 8 inches in diameter. Cut into 8 wedges and transfer to prepared baking sheet, spacing apart.
07 - Brush scones with extra cream for golden finish. Bake 16-18 minutes until golden brown and cooked through. Let cool on wire rack.
08 - Whisk powdered sugar with 2 tablespoons lemon juice. Add more juice for desired consistency. Stir in lemon zest.
09 - Drizzle glaze over cooled scones. Allow to set before serving.