Grease an 8x8 square baking dish with cooking spray and line with a parchment paper sling. Set aside.
Place cake mix, jello mix, canola oil, eggs, and vanilla extract into a large bowl.
Mix until combined.
Stir in white chocolate chips/chunks.
Transfer batter to prepared pan.
Use a spatula to gently press down the mixture.
Bake in preheated oven for 30-35 minutes, the top should look cooked, but the center will still be gooey, you don’t want to over-bake or you’ll end up with cake, not gooey brownies.
Cool completely in pan before cutting (they’ll fall apart otherwise).
Use the parchment sling to remove the brownies from the pan, then cut into squares and enjoy!