Place a rack in the center of your oven and preheat to 400 degrees F. Line a large baking sheet with parchment paper or a silicone baking mat.

Dice the butter into small pieces and place it in the freezer while you prepare the other ingredients.

Place the sugar in a large mixing bowl. Zest the lemon directly over the top (reserve the zested lemon for the glaze). With your fingers, rub the zest into the sugar until it is moist and fragrant.

To the bowl, add the all-purpose flour, whole wheat flour, baking powder, and salt. Whisk to combine.

Scatter the cold butter pieces over the top. With a pastry blender or fork, cut in the butter until the mixture resembles coarse crumbs. Some pieces may be the size of small pebbles and others as large as peas. If there are a few stubborn pieces of butter that won't break up, you can quickly use your fingers to rub them in.

In a separate bowl or large measuring cup, whisk together the Greek yogurt, milk, and egg until smoothly combined. Make a well in the center of the dry ingredients, then pour all of the yogurt mixture into it at once. With a fork, stir just until evenly moistened and the dough holds together. The mixture will seem dry at first but will even out (you can lightly use your hands to bring the dough together if needed). Gently stir in the blueberries.

With a cookie or ice cream scoop, drop the batter by 1/4 to 1/3 cupfuls onto the prepared sheet (each biscuit should be 3 or so inches wide). Leave at least 1 1/2 inches of space around each. Bake for 12 to 18 minutes, until the tops are golden and spring back lightly when touched and a toothpick inserted in the center comes out clean. Transfer to a wire rack.

While the blueberry biscuits bake, prepare the lemon glaze: In a small bowl, whisk together the powdered sugar and lemon juice until smooth. Drizzle over the warm biscuits. Enjoy!