Preheat oven to 375°F; position oven racks in upper and lower thirds. Line two large, rimmed baking sheets with parchment paper; set aside. 2.

Prepare the Cookies Beat together butter and sugar in the work bowl of a stand mixer fitted with paddle attachment on medium speed until light and fluffy, about 3 minutes. Add egg and vanilla; beat on low until combined, about 30 seconds.

Whisk together flour, baking powder, salt, and baking soda in a medium bowl. With mixer on low, gradually add flour mixture, beating until just combined. Gently fold in blueberries until evenly distributed. Set aside.

Prepare the Streusel Using a fork or hands, stir together flour, butter, sugars, cinnamon, and salt in a medium bowl until mixture is crumbly and holds together when squeezed.

Using a 1 ⅓-ounce (2 ½ tablespoon) (#24) scoop, scoop 24 cookie dough balls onto prepared baking sheets, about 2-inches apart. Top each cookie dough ball with about 2 teaspoons of the streusel, pressing firmly into dough to adhere (dough should flatten slightly). Freeze, uncovered, until firm, about 15 minutes.

Bake both sheets in preheated oven, rotating baking sheets top to bottom, halfway through, until cookie edges are set and streusel is lightly crisp, 16 to 18 minutes. Let cool to room temperature on baking sheets set on wire racks, about 20 minutes.

Prepare the Lemon Glaze Whisk together powdered sugar and lemon juice in a small bowl until smooth and easily drizzled (add more lemon juice, ½ teaspoon at a time, to reach desired consistency, if needed). Drizzle over cooled cookies.