Preheat oven to 375℉. Line two baking sheets with parchment paper.

In a large bowl, stir together the flour, sugars, baking powder, and salt. Mix in the blueberries and lemon zest.

Make a well in the center of the dry ingredients and pour in the heavy cream and vanilla extract. Stir everything together until ingredients are just moistened. Don’t over mix!

Turn dough out onto a floured surface. Knead for about a minute until everything is just about combined. Then separate the dough into two equal parts. (Can just eye it. Doesn’t need to be exactly the same weight.)

Flatten each half into an 8-inch disk and slice each one into 6 triangles. (see photos)

Place triangles about an inch apart from each other on a baking sheet and brush with the egg wash.

Bake scones for 20 minutes or until the tops and bottoms are golden.

In a small bowl, combine both ingredients into a thick but smooth-drizzle consistency. (May require more liquid to make the right consistency. You want it to slowly drizzle off the spatula.)

Transfer mixture to an icing bag or sandwich bag and cut a small tip off the bottom.

Drizzle over scones and let set.