In a large mixing bowl stir together the flour, sugar, baking powder, salt and garlic powder. Using a pastry cutter (or your fingers) cut the butter into the dry ingredients until the mixture resembles coarse sand. If the butter is feeling melted or warm, stick the mixing bowl in the freezer for a couple of minutes to keep the butter cold.
Make a well in the center of the ingredients and add the heavy cream and egg. Use a fork to whisk the egg into the heavy cream and then incorporate the wet ingredients into the dry until it starts to form a shaggy dough, but doesn’t fully come together. Add the cheddar cheese and chives and continue mixing the dough to evenly distribute the cheese and chives and form at thick dough. The dough shouldn’t be wet, but should stick together so you can easily form square. If the dough is too dry or crumbly add in a tablespoon of cream at a time until the dough comes together. Be sure to not over mix or overwork your dough.
Turn the dough out onto a clean work surface coated in flour. Pat the dough into a 9×9-inch square. It doesn’t need to be perfect, but try to keep it consistent in terms of thickness. Using a sharp knife cut the square in 9 equal scones. Place the squares on your prepared baking sheet two inches apart.
Place a small amount of cream in a bowl and using a pastry brush, brush the top of the scones. Bake at 400°F for about 25-30 minutes or until the scones are just starting to brown at the edges and a knife inserted into the middle comes out clean.