Prep. Preheat oven to 400º F. Line a rimmed baking sheet pan with parchment paper or a nonstick baking sheet.
Make the Dough. Whisk together flour, sugar, baking powder, and salt in a large bowl. Add butter to the bowl and cut into the flour with a pastry blender until the largest pieces of butter are about the size of a pea and the flour mixture resembles coarse meal. Stir in ¾ cup of heavy cream, lemon juice, and orange and lemon zests.. Press dough together between the palms of your hands. If it doesn't just hold together, add more heavy cream until is just holds together.
Prepare the Dough. Pour dough onto a lightly floured countertop or a pastry board. Pat dough into a large round disc, about an inch thick. Cut dough into equal sized wedges and place onto prepared baking sheet pan. Melt about 2 tablespoons butter and brush on top of dough.
Bake. Bake scones for 20-25 minutes or until they are just beginning to turn lightly brown. Remove from the oven.
Make the Glaze. Whisk all of the glaze ingredients together in a medium sized bowl until smooth and then drizzle on top of each scone after it has cooled for a few five minutes. Sprinkle with coarse sugar, if desired.
