Cream butter and sugars together until light and fluffy. Beat in eggs and vanilla.
In a separate bowl combine flour, cornstarch, baking soda and salt. Add to butter mixture.
Stir until combined. Stir in white chocolate chips. Carefully stir in the dried raspberries and blueberries Form into balls about an inch or slightly more in diameter.
Chill for at least 2 hrs or a couple days if you don't want to eat them right away.
Preheat oven to 350 and grease cookie sheet. Bake for 8-11 minutes until edges are lightly brown. Do not over-bake. The centers may still look doughy.
To make the cookies a bit prettier, you may press in a few additional chocolate chips and dried raspberries and blueberries. Press them gently into cookies that came straight out of the oven. Allow to cool on the cookie sheet for a minute before removing to a wire rack to cool completely.