Place oven rack in the middle and preheat to 400º F. Line a large baking sheet with parchment paper; set aside.

In a large bowl, whisk the flour, sugar, baking powder, salt, minced rosemary, ½ tablespoon lemon zest and all of orange zest. Grate frozen butter and add to dry ingredients. Incorporate the butter into the dry ingredients with your hands or with a mixer with a pastry attachment until the mixture is grainy and the butter chunks are the size of small pebbles. This will create wonderful air pockets that make the scones flaky and delicious.

Whisk the egg into the cream until incorporated. Gradually add the wet ingredients into the dry ingredients, mixing gently with a wooden spoon into a large ball.

With floured hands, transfer the dough to a clean, well floured surface. Press the ball into an 8" circle with uniform thickness. Using a floured pastry scraper, cut into 8 pieces.

Transfer to the lined baking sheet, placing the scones about an inch apart.

Bake for about 12 - 15 minutes or until lightly browned on the outside. Allow scones to cool for a few minutes then transfer to a wire rack to complete cooling.

Whisk powdered sugar together with fresh lemon juice and remaining lemon zest until smooth

Spread the glaze over scones. Allow the glaze to set; serve.