1box mix + ingredients called for or your favorite 13x9" recipe
Preheat oven to 325 degrees F. Line a 13-inch x 9-inch baking dish with parchment paper or foil and spray with nonstick cooking spray. Set aside.
In a large bowl, mix brownie batter. Pour ⅔ of the batter into the prepared baking dish and set the remainder aside.
In a medium sized bowl, beat the cream cheese, granulated sugar, egg yolk and vanilla together until fluffy and smooth.
Warm the raspberry preserves in the microwave for about 10 seconds.
Add dollops of the cream cheese mixture randomly around the brownie mixture. Then teaspoon-sized dollops of the raspberry preserves. Gently and carefully “spread” the remaining brownie mixture over and between the cream cheese and raspberry layers. Glide a knife a few times through the layers to create a swirl effect.
Bake in the preheated oven for 28-30 minutes or until a toothpick inserted in the center comes out clean. Cheesecake should be set in the center (not jiggly).
Cool completely in the pan before cutting into squares.