Ingredients:

  • 0.5 cup all-purpose flour
  • 0.33 cup granulated sugar
  • 0.25 cup cold unsalted butter, cubed
  • 0.25 tsp ground cinnamon
  • 1 cup unsalted butter, softened
  • 0.75 cup granulated sugar
  • 0.25 cup light brown sugar, packed
  • 1 large egg
  • 1 egg yolk
  • 2.5 tsp vanilla extract
  • 2.75 cups all-purpose flour
  • 1 tsp cornstarch
  • 1 tsp baking powder
  • 0.5 tsp salt
  • 1.5 cups blueberries
  • 1 cup powdered sugar
  • 2 tbsp heavy cream

Instructions:

  1. In a small bowl, combine 1/2 cup flour, 1/3 cup sugar, and cinnamon. Rub 1/4 cup cold cubed butter into the mixture until coarse crumbs form. Refrigerate immediately.
  2. In a large bowl or stand mixer, cream together 1 cup softened butter, 3/4 cup granulated sugar, and 1/4 cup brown sugar until light and fluffy.
  3. Beat in the large egg, egg yolk, and 2 teaspoons of vanilla extract until well combined.
  4. Whisk together 2 3/4 cups flour, cornstarch, baking powder, and salt. Gradually mix the dry ingredients into the wet ingredients until a dough forms.
  5. Gently fold in the blueberries by hand to prevent the dough from turning purple.
  6. Scoop 3-tablespoon portions of dough onto parchment-lined baking sheets. Generously press the chilled streusel onto the top of each dough ball.
  7. Bake at 350°F (175°C) for 12–15 minutes until the edges are golden brown. Let cool on the pan for 10 minutes.
  8. Whisk together powdered sugar, heavy cream, and remaining 1/2 teaspoon vanilla. Drizzle over the cooled cookies.