Instructions

1. Preheat the oven to 400 F degrees.
2. Cut butter into to small, dime-sized pieces and place in refrigerator to keep cool.
3. In a 2 cup measuring cup or small bowl, combine 1 cup milk with 1 tsp lemon juice. Let sit at room temperature for 5 minutes - turning the standard milk into buttermilk.
4. In a large bowl combine the flour, sugar, baking powder, lemon zest, and salt. Whisk to combine, then add butter to the flour bowl. Use a form or pastry blender to cut in the butter until the pieces are about pea sized.
5. In a small bowl whisk the egg yolk, buttermilk and vanilla extract together. Add buttermilk mixture to the flour mixture and stir until the dough is just combined.
6. Transfer the dough to a floured work surface and knead it gently about 3 times. Push or roll dough into a rectangle about 3/4 of an inch thick and about 12 inches long. Top with blueberries and fold over twice. Reshape into a long rectangle and cut into wedges.
7. Place the wedges onto a parchment lined baking sheet. Bake for about 20 minutes or until golden.
8. While baking, combine all glaze ingredients and whisk until smooth. When the scones are done, let cool on a rack and drizzle generously with the glaze.