Preheat oven to 375°F (190°C) and line two baking sheets with parchment paper or silicone mats. If using frozen blueberries, pat them dry with paper towels.
In a medium bowl, combine flour, sugar, and cinnamon, then cut in cold cubed butter with a fork or pastry cutter until the mixture resembles coarse crumbs. Refrigerate until needed.
Beat softened butter and sugar together on medium speed for 2–3 minutes until light, fluffy, and pale in color, scraping down the bowl as needed.
Beat in the egg, vanilla extract, and almond extract on medium speed for about 30 seconds until smooth and well combined.
In a separate bowl, whisk together flour, baking powder, and salt until evenly distributed.
Add half the flour mixture to the butter mixture on low speed, mix in the milk, then add the remaining flour and mix until just combined — do not overmix. The dough will be thick and slightly sticky.
Using a spatula, gently fold the blueberries into the dough, taking care not to crush them, until evenly distributed.
Use a 2-tablespoon cookie scoop to portion dough onto prepared baking sheets, spacing cookies about 2 inches apart (about 24 cookies total).
Sprinkle a generous amount of chilled streusel over each cookie and gently press it in so it adheres during baking.
Bake for 12–14 minutes, rotating pans halfway through, until edges are lightly golden and centers still look slightly soft.
Let cookies cool on the pan for 5 minutes, then transfer to a wire rack to cool completely — or enjoy warm!