In a medium bowl, combine the flour, cornstarch, baking soda and salt. Set aside.

To the bowl of a stand mixer, add the butter, cream cheese, granulated sugar and brown sugar. Using the paddle attachment, combine on medium speed until smooth, about 2 minutes.

To the butter mixture, add the egg and vanilla extract. Mix on medium speed until combined. Stop the mixer and scrape the sides of the bowl.

With the mixer on low speed, gradually add the flour mixture and mix until combined - be careful not to over mix. Stop the mixer.

Add the crushed Oreos and white chocolate chips and stir by hand until combined.

Cover the bowl with plastic wrap and chill in the refrigerator for 30 minutes.

Preheat oven to 350°F.

Line baking sheet with parchment or a silicone baking mat. Scoop cookies onto the prepared cookie sheet, about 2 Tablespoons each in size. Place cookies 2 inches apart.

Bake 12 minutes, or until the edges start to brown.

While cookies are baking, combine all ingredients for the Lemon Sour Cream Icing in a bowl. Stir together with a wire whisk until smooth. Add enough lemon juice for a thick consistency that can be spooned onto the cookie. Set icing aside.

Remove cookies from oven. With the back of a teaspoon, gently press a well into the center of each cookie. Spoon a teaspoon of icing into each well. Allow the cookies to cool about 10 minutes on the pan before transferring to a wire rack to cool completely. Icing will set as the cookies cool.

Serve and enjoy!