Place the 2 cups flour (spooned and leveled) in the fridge for 10–20 minutes if possible to chill. Keep the 8 tablespoons cubed butter frozen until needed. Line a sheet pan with parchment paper or a silicone baking mat.
Zest both oranges to yield about 2 tablespoons orange zest and juice both oranges to yield about 2 tablespoons orange juice; set the juice aside for the glaze.
In a large bowl, combine the 2 tablespoons orange zest with the 1/2 cup granulated sugar. Rub the zest into the sugar with your fingers until the sugar is fully fragrant and orange-infused.
Add 2 teaspoons baking powder, 1/2 teaspoon salt, and the chilled 2 cups flour to the orange-sugar mixture. Whisk briefly to combine.
Add the frozen cubed butter to the dry ingredients. Use a pastry cutter (or two forks / your fingertips) to cut the butter into the flour mixture until the butter pieces are about pea-sized and evenly distributed.
Measure out the heavy cream: use 1/2 cup (8 tablespoons) of the 11 tablespoons heavy cream for the wet mixture and reserve the remaining 3 tablespoons for brushing and adjustments later. In a small bowl, whisk together the 1/2 cup heavy cream, 1 large egg, 1 teaspoon vanilla bean paste (or extract), and 1/4 teaspoon almond extract (optional) until smooth.
Make a shallow well in the center of the dry ingredients and pour in the wet mixture. With a wooden spoon, gently stir just until a shaggy dough begins to form.
Immediately add the 3/4 cup dried tart cherries and mix as little as possible—just until the cherries are evenly distributed and the dough is mostly combined.
Very lightly flour a work surface. Turn the dough out onto the surface and, using lightly floured hands, bring it together into a rough ball, handling it as little as possible. If the dough is too sticky, sprinkle a tiny bit more flour; if it seems too dry, add 1–2 tablespoons of the reserved heavy cream (from the 3 tablespoons set aside).
Press the dough into a flat disc. Cut the disc exactly in half and shape each half into a smaller disc about 5 inches wide.
Wrap each disc tightly in plastic wrap and chill in the refrigerator for 10 minutes.
Remove the chilled discs and, using a very sharp knife, cut each disc into 8 equal wedges (16 scones total). Arrange the wedges on the prepared sheet pan about 2 inches apart.
Pour the remaining reserved heavy cream (about 2–3 tablespoons) into a small dish. Brush the tops of the scones with this cream and sprinkle with white sparkling sugar, if using.
Refrigerate the assembled scones on the pan for 20 minutes while you preheat the oven to 400°F.
Bake the scones at 400°F for 17–25 minutes, until the edges are lightly golden and the tops are just browned (watch closely; they typically take about 19–20 minutes). Remove from the oven and let cool on the baking sheet for a few minutes, then transfer to a cooling rack to cool completely.
Make the glaze by whisking together the 1 cup powdered sugar and the reserved 2 tablespoons orange juice. Add additional orange juice, a drop at a time, only if you want a thinner glaze.
When the scones are completely cool, drizzle the orange glaze over them. Let the glaze set before serving.