Place the butter in the freezer for 15 minutes. Next, chop the cold butter in half lengthwise. Turn it on its side and cut lengthwise again. Slice the butter into thin slices. Place butter in the fridge to stay cold as you prepare the rest of the ingredients.
Line a baking sheet with parchment paper. Dust a clean workspace lightly with flour.
In a large mixing bowl, combine the sugar and lemon zest. Rub the zest into the sugar with your fingertips.
Use a spatula or whisk to stir the flour, baking powder, cardamom and salt into the sugar mixture til just combined.
Add the chopped butter to the mixture. Use a pastry cutter, two forks, or your fingertips to cut/work the butter into the mixture until the butter is about the size of peas. Stir half of the white chocolate in with a spatula til combined. Create a well in the middle of the mixture.
In a small bowl, use a fork to whisk to combine the egg yolk, vanilla and ½ cup of heavy cream. Pour the mixture into the well. Use a fork to slowly combine the wet and dry ingredients. If you see some dry spots, add a tablespoon more of heavy cream at a time, as needed. Stir mixture with a fork in the bowl until it's too hard to keep mixing with a fork. Add the fresh or frozen raspberries. Stir just to combine.
Turn dough out onto your lightly floured workspace. Lightly flour your hands. Lightly knead the dough briefly (fold it over on itself and rotate it a few times). Do not overmix. Dough shouldn't be too dry and should be moist but not wet. If dry there are some dry spots, add a bit more heavy cream and if it's too sticky (sticking to your hands a lot), add a little more flour.
Use your hands to pat the dough into a circle between 6 and 8 inches. Use a long sharp knife or bench scraper to slice the dough into 8 triangles. Place scones on a baking sheet. Cover with plastic wrap and chill in the refrigerator or freezer for 1 hour.
Preheat oven to 400 F. Brush tops and sides with heavy cream.
Place scones evenly about 2 inches apart on a baking sheet lined with parchment paper for 17-22 minutes or until lightly golden brown around the edges and lightly browned on top.
Allow scones to cool to room temperature before drizzling with white chocolate.
Place the remaining white chocolate chips in a bowl. Microwave it for 15 seconds. Give it a stir then microwave it for 15 more seconds. Stir again. If needed, microwave it for 15 more seconds. Drizzle or spread over the cooled scones. Allow the white chocolate to set a few minutes or enjoy right away!