Preheat oven to 200°C. Line a baking sheet with parchment paper.
In a medium bowl, mix sugar and lemon zest, add in flour, baking powder and salt and mix until combined.
Add the butter to the flour mixture and squish it between your fingers until the mixture is crumbly.
In a small bowl, whisk the yogurt, egg and vanilla until combined.
Add the yogurt mixture into the flour mixture, mix until a dough starts to form. Now, fold in raspberries.
Place your dough on a lightly floured surface and roll out into a 17-cm circle about 2-cm thick.
Use a knife to cut the circle into 8 triangles; place them on the baking sheet leaving about 1 inch apart.
Bake for 15-20 minutes or until golden.
Allow to cool for 10-20 minutes before adding the glaze.
Make the glaze
In a bowl, whisk together icing sugar, vanilla extract and lemon juice until smooth. Drizzle the glaze onto your scones.
Notes
Here are some tips that I am basing on a couple of failed experiments:
It is better if the ingredients are cold.
Knead the dough lightly. This will prevent the berries from breaking and the batter, in turn, turning pink.
Fresh raspberries are better than frozen raspberries in maintaining the scones' visual appeal.
The batter for scones is thick, and hence you'll want to use a sturdy spoon or spatula to mix it. Initially, the flour mixture might not seem like it will be incorporated, but keep going and avoid adding more liquid.
Refrigerating the scones at least 15 minutes before baking results in tender scones and helps in shape retention.
If you are planning on storing the scones, make sure that you put them in airtight containers after they have cooled down completely before putting them in the fridge/freezer.
Recipe Variations
You can substitute the raspberries with any other berries of your choice.
If the scones are too tart for your taste, you can use vanilla glaze or icing instead of lemon glaze.
Regular Greek yogurt can be used instead of the lemon-flavored alternative for milder flavours.
If you prefer your desserts extra sweet, you can top the scones with granulated sugar as per your preference.