Pop butter in the freezer. Move the oven rack to the lower third of the oven and preheat to 400°F. Line a large sheet pan with a silicone baking mat and set aside.
In a large bowl, whisk together the flour, 1/4 cup granulated sugar, brown sugar, baking soda, baking powder, and salt.
Grate the frozen butter on the large holes of a cheese grater, or cut it into small cubes (pea-sized) and pop it back in the freezer until solid.
Use a pastry cutter or two butter knives to press and slice the butter into the dry ingredients until you have a crumbly mixture with small chunks of butter. These cold butter pieces help create flaky layers. Stir in chocolate chips. Refrigerate while preparing wet ingredients.
In another bowl, combine vanilla extract, almond extract, Greek yogurt, and egg. Whisk until well combined and smooth.
Add the wet ingredients to dry and mix with a strong spatula until just combined. Use your hands to press the dough into a large ball. The dough will be slightly sticky, and it may seem too dry to form a ball. Keep kneading and pressing it gently, and it will come together. Keep in mind that the less you mix and knead, the better the texture will be (see note 1).
Using your hands, shape the mixture into a 5.5-inch disc about 1 inch thick. Tightly wrap disc with plastic wrap and pop in the freezer for 20 minutes. Remove and unwrap. With a sharp knife, cut the disc into 8 equal triangles, using decisive, swift cuts instead of a sawing motion. Separate the triangles and place them on the prepared cookie sheet, leaving about 1 inch of space between each.
Brush the tops of the scones with heavy cream. Sprinkle with the remaining 1 teaspoon of sugar. Place the sheet pan with the scones in the fridge and chill for 20 minutes.
Remove scones from fridge and place in the fully heated oven. Bake until lightly golden around the edges and barely golden on top, about 14–16 minutes.
For the glaze, whisk the milk or heavy cream, powdered sugar, and vanilla extract together until smooth. Add more milk or heavy cream as needed but keep the glaze thick.
Remove the scones from the oven and let sit on the sheet pan for 5 minutes to finish cooking. Allow them to cool to room temperature, then drizzle the glaze on top using a spoon.
Video
Notes
Note 1: Handle dough as little as possible. Stop mixing once it comes together. Cold butter and minimal gluten development are key for flaky scones.Storage: These scones are best the same day and soften overnight. Freeze unbaked scones for best results. Freeze until solid, transfer to an airtight bag, and store up to 1 month. Bake from frozen, adding 1 to 3 minutes.