Step 1

Preheat the oven: To 350 degrees F (175 degrees C). Line 2 baking sheets with parchment paper; set aside.

Step 2

Combine the dry ingredients: Whisk together flour, baking powder, baking soda, and salt in a medium bowl. Set aside.

Step 3

Combine the wet ingredients: Beat the sugar, cream cheese and butter in a large bowl with an electric mixer until light and fluffy, about 2 minutes. Mix in egg, vanilla extract, and sour cream until well combined.

Step 4

Mix the two: Add all the flour mixture and stir until just combined. Do not overmix.

Step 5

Finish the cookie dough: Gently fold in blueberries. Drop 1 1/2 tablespoon-sized balls of dough onto the prepared baking sheets about 2 inches apart.

Step 6

Bake the cookies: Bake in the preheated oven until the bottom of the cookies just begins to brown, 15 to 18 minutes, mine took the full 18 minutes. Cool on the baking sheets for 5 minutes then transfer to a wire rack and cool completely.