Preheat oven to 425 degrees F (220 degrees C). Line a baking sheet with parchment paper.
Whisk all-purpose flour, whole wheat pastry flour, baking powder, and salt together in a large bowl. Rub in cubed butter with your fingers until mixture resembles coarse meal. Fold in blueberries and lemon zest.
Whisk 5 tablespoons heavy cream, honey, and egg together in a small bowl. Pour over the flour mixture; mix gently with your hands until dough just comes together.
Turn dough out onto a lightly floured work surface. Pat dough into a 6-inch round about 1 inch thick. Cut dough into 12 rounds using a round cutter.
Transfer rounds to the prepared baking sheet. Drizzle remaining 2 tablespoons heavy cream over the tops.
Bake in the preheated oven until golden brown, 12 to 15 minutes.