Line two baking sheets with parchment paper.
In a large bowl, combine cake mix and baking powder. In a separate bowl, whisk together eggs, oil, and vanilla by hand until well combined.
Pour egg mixture into bowl with cake mixture. Stir until a dough forms. Be sure to fully combine. Mix in the white chocolate chips.
Drop rounded balls of the dough onto your baking sheet. Since they flatten out quite a bit, make sure the balls are taller than wide on your cookie sheet, about 2 inches apart.
Bake for 10 minutes. Do not let them brown in the oven. Once slightly cooled remove from sheets to finish cooling on wire racks. Cookies will appear slightly undercooked, but that's ok. They firm up and flatten as they cool. Allow to cool for at least 10 minutes. Enjoy!
Cookies will stay fresh, covered, at room temperature for up to 1 week. You can make the cookie dough in advance and hold it in the refrigerator for up to 3 days. Allow dough to come to room temperature before spooning it onto the prepared baking sheet. Alternatively you can freeze your baked cookies up to 3 months. Or freeze your unbaked cookie dough balls for up to 3 months. Bake the frozen cookie dough balls for an extra minute, without thawing.