Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.

In a large bowl, whisk together the flour, sugar, baking powder, salt, and lemon zest.

Add the cold cubed butter and use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.

In another bowl, mix the heavy cream, egg, and lemon juice until well combined.

Pour the wet ingredients into the dry ingredients and stir until just combined.

Turn the dough onto a lightly floured surface and gently knead it until it comes together. Do not overwork the dough.

Shape the dough into a circle about 1-inch thick and cut into 8 wedges. Place them on the prepared baking sheet.

Bake for 18-20 minutes, or until the scones are golden brown on top.

Remove from the oven and allow to cool slightly before serving.