In a medium size mixing bowl, whisk all-purpose flour, sugar, fine sea salt, and 2 teaspoons baking powder.
Use a cheese grater to grate ½ cup unsalted butter into the bowl. Toss the grated butter with the flour mixture with a fork to coat and separate the pieces of butter.
In a separate bowl, whisk sourdough starter discard, 1 large egg, vanilla extract, almond extract, heavy cream, poppy seeds, fresh lemon juice, and lemon zest until smooth. Pour into the dry ingredients and use a fork to gently mix. The dough will be crumbly, so resist the urge to add more liquid.
Dump the dough onto a clean work surface and use your hands to press and shape the dough into an 8" disc shape. (If needed, use a small amount of flour to help it from sticking to the surface.)
Using a bench scraper or a large knife, cut the dough into 8 wedges. Arrange the wedges on a parchment-lined baking sheet, leaving space between each wedge. Place the baking sheet in the fridge to chill for 30 minutes.
When ready to bake, preheat the oven to 400°F (204°C). Bake for 20-23 minutes or until the scones are golden brown. Remove from the oven and let them cool completely on the baking sheet.
In a small bowl, whisk together 1 cup powdered sugar, 2 tablespoons fresh lemon juice, and a pinch of salt. Drizzle the glaze over top each scone and let it set. Enjoy!
