Preheat oven to 375°F. Line a large baking sheet with parchment. Set aside.
In a medium-size mixing bowl, use a whisk to sift together, flour, sugar, baking powder, poppy seeds, lemon zest and salt.
Use a pastry blender or a food processor to cut butter into dry ingredients until it resembles cornmeal.
In a separate bowl, whisk together buttermilk, lemon juice and eggs.
Make a well in the center of dry ingredients, adding wet. Mix through with a fork until moistened. Add more buttermilk in small amounts, if needed just until the dough comes together but, not too wet. (Before adding more liquid, squeeze a small amount in your hand. If it holds together you're good to go)
Turn dough out onto a lightly floured non stick surface. Knead lightly just to bring it together then shape dough into an 8 inch round about ¾ inch thick. (If making in advance, you can wrap and chill at this point)
Use a sharp knife to cut into 8 even wedges. Transfer to baking sheet leaving 2 inches between. Brush tops with buttermilk.
Bake for 25 minutes or until lightly golden and a toothpick inserted into the center shows moist crumbs. Carefully remove to a cooling rack while you make the glaze.
Glaze: Whisk together powdered sugar, lemon juice and zest. Drizzle over warm scones sprinkling with additional zest, if desired.
Serve immediately with blueberry preserves, lemon curd and whipped cream.