Preheat oven to 350-degrees.

In the bowl of a stand mixer, affixed with the paddle attachment, add the butter and both sugars. Mix on medium-high speed until light and fluffy. Add the egg and egg yolk and mix until incorporated. Add the vanilla extract and strawberry extract (if using). Mix until combined.

Turn the mixer to low speed and add the flour, salt, baking soda, baking powder and cornstarch. Mix until barely combined.

Remove the bowl from the mixer and use a rubber scraper to ensure all the ingredients are incorporated.

Cut the Pop-Tarts into 15 small pieces and set aside. Break up the remaining Pop-Tart pieces and fold into the cookie dough.

Line two baking sheets with parchment paper. Scoop standard sized cookie dough balls and roll into the crushed cereal or sprinkles. Place cookie dough balls on the baking sheets.

Bake cookies, one baking sheet at a time for 9-minutes in 350-degree oven. As soon as you remove the cookies from the oven, press a Pop-Tart piece on top. Allow cookies to cool and set on the cookie sheet for 10-minutes before transferring to a wire rack to finish cooling. Repeat process with remaining baking sheets of cookie dough balls.