Preheat the oven to 350° F.
Whisk the dry ingredients- all purpose flour, baking soda, salt, Dry Instant Vanilla Pudding Mix , Dry Vanilla Cake Mix, in a medium bowl and set aside.
In a stand mixer using the paddle attachment (or a bowl with a hand mixer), beat the butter, light brown sugar and granulated sugar for about 3-5 minutes, until light and fluffy.
Add in the egg and vanilla. Mix until combined.
Add the dry ingredients to the mixer a little at a time and mix together until fully incorporated, about 30 seconds. Fold the sprinkles, along with the white chocolate chips.
Chill the dough for about 30 minutes too an hour, longer if possible.
Scoop cookie dough onto a parchment paper-lined sheet tray with a standard cookie scoop.
Bake for about 10-12 minutes, then allow to finish baking on the hot cookie sheet for about 2ish minutes
Top with extra white chocolate chips and sprinkles if you'd like while the cookies are still warm. Transfer to a wired rack. Enjoy!