In a big mix bowl, beat softened butter for 1 minute until it is smooth and creamy. Add both brown sugar and granulated sugar and beat until the color looks pale and fluffy.

Beat in egg and vanilla extract at high speed. Scrap the bottom of the bowl using the spatula in intervals.

In a separate bowl mix well all dry ingredients. Slowly beat in the dry ingredients into the wet mixture until well incorporated.

Add white chocolate chips and blueberries and mix on low speed until distributed evenly in the mixture.The mixture will look quite dry but will come together.

cover the dough tightly with cling wrap and refrigerate for 2 hours or up to 2 days.(This step can't be skipped)

Remove cookie dough from the refrigerator and allow to sit at room temperature for 10 minutes-- if the cookie dough chilled longer than 2 hours, let it sit at room temperature for about 30 minutes. This makes the cookie dough easier to scoop and roll. Preheat oven to 175-degree celsius.

Once chilled, remove the dough. Scoop 1 tablespoon of dough and roll into a smooth ball using your hands. press slightly in between your palms and flatten the dough balls.

Arrange the shaped cookies dough on a baking tray lined with parchment paper. Bake in batches for 8 -10 minutes until slightly golden brown at the edges and just set.

The cookies might still appear soft at the center but once it cools down and comes to room temperature they will harden.

Place the cookies on a cooling rack. After cooled completely, store in an airtight container.