Preheat the oven to 375° F. Line a baking sheet with parchment paper and set aside.
In a large bowl, whisk together the flour, sugar, poppy seeds, baking powder, salt, and lemon zest. Add the cold, grated butter to the mixture and cut in using a pastry cutter or two forks until you get a crumbly mixture.
Whisk together the milk, egg, and vanilla and pour into the butter mixture. Mix until a crumbly dough starts to form (will be a bit sticky). Dump this dough onto a floured surface and shape it into an 8 inch round disc. Don't overmix it here.
Cut your disc into 8 triangles and move to the baking sheet. Put them in the fridge to chill for 20 minutes. Once they are chilled, remove from the fridge and brush the tops with heavy cream or milk.
Bake for 18-22 minutes or until lightly golden brown around the edges. Once done remove them from the oven and allow them to cool for 5-10 minutes before glazing.
make the glaze
In a medium-sized bowl, whisk together the powdered sugar, lemon juice, heavy cream, and lemon zest until smooth. Pour this over the scones and enjoy!
Use grated butter- this helps keep the butter frozen and mixes well in the batter!
Make sure to measure your flour correctly- spoon and level is my favorite method. Use a spoon to fluff up the flour, then gently scoop it into your measuring cup without packing it. Then use the back of a butter knife to level it off.
Don't over mix the scones- over-mixing the scone batter can lead to dense scones that don't rise well. Be sure not to over mix!
Chill before baking- this is a necessary step because you want to make sure the butter you just mixed into the dough is cold before baking!
Storing & Freezing
These scones are best fresh out of the oven and the day of. They can be stored in an airtight container at room temperature for 2-3 days and I would avoid glazing them before storing. They can be frozen for up to 2 months.
If you want to make the dough and freeze it before baking, follow the instructions up until you cut them into triangles and then place in a freezer safe container or bag. Defrost by allowing them to sit at room temperature and then brush with heavy cream and bake.