Preheat oven to 350 degrees F. Line baking sheets with silicone baking mats or parchment paper.
In the bowl of a stand mixer, cream together the butter with brown sugar and sugar until light and creamy.
Add in egg, egg yolk, and vanilla extract and mix until combined.
In a separate bowl combine flour, cornstarch, baking soda, and salt.
Add into sugar mixture and beat until well mixed. Fold in the white and chocolate chips.
Drop each tablespoon of seedless raspberry jam in separate areas of the bowl. Using a rubber spatula swirl the jam into the cookie dough. Do not stir too much or your dough will turn pink.
Using a medium cookie scoop, drop dough onto cookie sheet. If the dough is warm, refrigerate 10 minutes before baking.
Bake for 12 minutes until cookies are set and edges are golden.
Remove from oven and let cookies cool on the baking sheet for about 5 minutes, then transfer to a cooling rack. Repeat with remaining dough.