01 -
Preheat your oven to 175°C and line two baking sheets with parchment paper.
02 -
In a medium bowl, whisk together 2 cups of flour, baking powder, baking soda, salt, oats, and cinnamon.
03 -
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy (about 3-4 minutes).
04 -
Beat in the egg and vanilla extract until well combined.
05 -
Gradually add the dry flour mixture to the wet mixture, stirring until just combined. Gently fold in the blueberries, being careful not to break them.
06 -
In a separate bowl, combine 1/2 cup flour, 1/4 cup granulated sugar, brown sugar, and cinnamon. Add the cold cubed butter and use your fingers or a pastry cutter to mix until crumbly.
07 -
Using a cookie scoop or tablespoon, drop cookie dough onto the prepared baking sheets, spacing them about 5 cm apart.
08 -
Generously sprinkle the streusel topping over each cookie dough mound.
09 -
Bake in the preheated oven for 12-15 minutes or until the edges are lightly golden and the centers are set.
10 -
Allow cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.