Add 2 cups flour, ½ cup sugar, 1 tablespoon baking powder, and ½ teaspoon salt to a large bowl
Whisk or fork mix the dry ingredients
Grate or shred 1 frozen stick of butter and mash it into the flour mixture using a pastry cutter or hands
Add 1 cup fresh blueberries and lightly coat them in the flour mixture
In a smaller bowl, combine ½ cup sourdough discard, 2 tablespoons heavy cream, 1 teaspoon vanilla extract, and 1 egg
Whisk the wet ingredients until combined
Pour wet ingredients into dry ingredients and fold with a rubber spatula until no dry flour remains
Lightly flour work surface and dump dough onto it
Form dough into an 8 inch round disc
Preheat oven to 400 degrees and line a baking sheet with parchment paper
Cut the disc into 8 equal triangular pieces
Place scones on baking sheet and sprinkle with coarse sugar
Bake for 20-25 minutes until golden brown
While baking, prepare lemon glaze by mixing ½ cup powdered sugar with juice from ½ lemon
Brush lemon glaze on warm scones when they come out of the oven
