Add the flour, baking powder, salt, ground cardamom, and brown sugar to a large bowl and whisk the ingredients together for about 30 seconds. Use your fingers to break up any large clumps of brown sugar.

Use a box grater to grate the frozen butter into the dry ingredients. Use your fingers to toss the butter and flour together and combine. Add the cream to the flour-butter mixture and use a silicone spatula to mix the cream into the dry ingredients. The dough will start to come together, but there will still be some flour at the bottom of the bowl.

Dump the dough onto a work surface and the knead the remaining bits of flour into the dough by folding the dough over and pressing it together. Do this about 3 to 4 times. Form the dough into an 8-inch circle. I sometimes use an 8-inch cake pan to get an even circle. Cut the dough into 8 wedges. Place the scones on a plate and refrigerate for 45 minutes.

Preheat the oven to 400 degrees F.

Place the scones on a half-sheet baking tray lined with parchment paper. Whisk together the egg and milk. Brush the tops of the scones with the egg wash. Bake for 23-27 minutes until the tops are golden brown and the scones have increased in height.

Allow the scones to cool to room temperature if adding the lemon glaze. Combine the powdered sugar and 1 tablespoon of lemon juice in a bowl and stir together. Add the remaining lemon juice 1 teaspoon at a time until the desired consistency is achieved.

Drizzle the glaze over the cooled scones.