Preheat oven to 400 degrees and line a baking sheet with parchment paper, set aside.
In a large bowl, stir sugar and orange zest together until sugar is moistened and zest is evenly distributed. Set aside.
In a medium-sized bowl, gently toss remaining dry ingredients through salt. Set aside.
In a separate small bowl, whisk yogurt and egg until completely smooth. Set aside.
Combine flour mixture with sugar and orange zest, and gently toss to combine. Grate frozen butter into mixture. Fold in the butter until the
mixture resembles a coarse meal. Gently stir in yogurt and egg mixture until just combined. Knead the dough inside the bowl, then form a ball.
Set dough in freezer for about 10 minutes.
Place dough on a lightly floured surface, and lightly pat into an 8-inch circle about 1 inch thick. Use a very sharp knife to cut into 8
triangles (like a pizza). Transfer triangles onto parchment paper lined baking sheet, leaving about an inch between each one.
Bake scones for 15-17 minutes on center rack until the tops begin to golden. Do not take them out too early or they will be too soft.
Allow them to cool for 10 minutes on the pan before transferring onto a wire rack to finish cooling.
To make the glaze, stir together melted butter, confectioner’s sugar, vanilla and Simply Orange until smooth. Add orange zest once
butter mixture has completely cooled. Pour into small resealable bag, close and snip small corner of bag to create a piping bag.
Squeeze a drizzle over tops of the scones, and sprinkle with additional orange zest as desired.