Preheat your oven to 425°F (220°C) and line a cookie sheet with parchment paper.

In a large mixing bowl, whisk together the flour, baking powder, baking soda, and salt.

Cut in the cold butter and lemon zest into the flour mixture until it resembles coarse meal.

In a separate bowl, whisk together the beaten egg, maple syrup, and Greek yogurt until smooth. Pour this into the dry ingredients and stir to form a sticky dough.

Fold in the frozen blueberries gently to avoid breaking them.

Turn the dough onto a floured surface and pat it into a rectangle about 1-inch thick; roll it up like a jelly roll.

Cut the rolled dough into triangles or desired shapes and arrange them on the baking sheet.

Bake for 12-14 minutes until golden brown and fluffy, then cool slightly on a wire rack.

Whisk together the Greek yogurt, powdered sugar, and lemon juice for the glaze, then drizzle over the cooled scones before serving.