• Adjust the oven rack to the middle of the oven. Heat oven to 400ºF (204ºF). Line a baking sheet with parchment paper; set aside.
• Using a box grater, grate butter (10 tablespoons) and freeze.
• Whisk the milk and sour cream together, then place in the refrigerator.
• Whisk flour, sugar, cinnamon, nutmeg, baking soda, baking powder and salt in a medium sized bowl. Remove butter from freezer and add to the flour mixture. Toss mixture with a fork until butter is dusted with flour evenly. Continue to use a fork, pastry blender, or 2 butter knives to combine until the mixture comes together in pea-sized crumbs. Try not to handle the dough too much with your hands so the butter does not melt.
• Add the cold milk mixture to flour mixture, gently folding with a spatula until just combined
• Flour a work surface and toss mixture onto work surface. Dust dough with flour and knead with your hands 6 to 8 times until the dough comes together. Add flour to prevent sticking, as needed. Refrigerate for 5 minutes.
• Shape the dough into a 12 inch square. Sprinkle apples on top and press them into the dough. Fold into thirds, bringing one edge to the center, then bring the opposite edge to the center, like an envelope. Roll out the dough with a rolling pin just to even out and flatten the dough. Reshape into a long rectangle. Then, bring the short end to the center and bring the opposite short end to the center of the dough. Roll out the dough into a 6 1/2 by 6 1/2 square making sure edges are sealed.
• Flour the dough. You should have a nice square of dough that is somewhat easy to work with. Cut the square in half, then half again in the opposite direction, forming four equally sized squares. Then, cut each square diagonally, making 8 triangles. Arrange each triangle on prepared sheet pan. Brush each scone with heavy cream and sprinkle with course sugar.
• Bake for approximately 20 minutes or until lightly browned. Remove from baking sheet and cool on a wire rack.

Make Glaze:

• In a small bowl, whisk together ingredients. If glaze is too thick, very gradually add more milk, until desired thickness. Drizzle over cooled scones.