Preheat oven to 200ºC (400ºF).
Cream butter, sugar, and brown sugar together until light and fluffy.
Beat in egg.
Whisk together flours, baking powder, baking soda, and salt in a bowl.
Add the flour mixture a little at a time until incorporated.
Stir in chocolate and blueberries.
Bake 10-12 minutes.
