Preheat oven to 375 degrees.

In a large bowl, whisk the flour, sugar, baking powder and salt together. Cut the cold butter into cubes, then add it to the flour mixture. Using a pastry cutter or just your fingers, work the butter and flour together until the mixture resembles coarse sand.

Pour in the cream, lemon juice, lemon zest and 1 tsp. sage. Stir together. Dump the batter onto a flour surface and roll until 1-2 inches thick. Cut into triangles and place them onto a parchment-lined baking sheet.

Brush the scones with remaining heavy cream and dust with sanding sugar. Sprinkle the remaining sage leaves on top. Bake 23-25 minutes. Allow to cool before glazing.

To make the glaze, whisk lemon juice and sugar together until smooth.