• Preheat the oven to 400 degrees. Line a sheet pan with parchment paper.
• In the bowl of an electric mixer fit with the paddle attachment, mix flour, sugar, baking powder, salt and cardamom.
• Add the cold grated butter and mix at the lowest speed until the butter is mostly combined and the dough looks craggy.
• Combine the egg, ½ cup of heavy cream and vanilla. With the mixer on low speed, slowly add to the flour and butter mixture. Mix until just blended. The dough will look lumpy and may not be fully incorporated yet!
• Add the chopped plums and mix on low until just combined.
• Dump the dough onto a well-floured surface and form it into a large disc pressing any dry ingredients into the dough to combine.
• Mold the dough into a circle, about 1-inch thick. You should still see small pieces of butter in the dough.
• Slice the circle into 8 wedges. Place them onto the prepared sheet pan. Brush the tops of the scones with the remaining 1 tablespoon of heavy cream.
• Freeze the dough for 30 minutes or refrigerate the dough for about 1 hour prior to baking.
• Bake for about 14-16 minutes, until the bottoms are starting to turn golden brown. Let the scones cool and then pour the glaze onto the scones.
• Let the scones cool for about 15 minutes and then pour the glaze onto the scones.

Glaze

• Whisk together powdered sugar and cardamom.
• Add the heavy cream and vanilla and stir until smooth. If a thinner consistency is desired, add more heavy cream by the teaspoon to thin it out.