Combine the cake mix, cornstarch and salt in a large mixing bowl. Set aside.
1, (15.25 oz. box) red velvet cake mix, 1 tsp. cornstarch, 1/2 tsp. salt
Cream the butter and sugar together using a stand mixer fitted with the paddle attachment, on medium speed until light and fluffy, ~2-3 minutes. 8 Tbsp. unsalted butter, cold, cut into cubes, 1/3 cup sugar
Add the eggs and vanilla extract and use a rubber spatula to knock mixture off edges of mixing bowl as needed.
2 large eggs, 1 tsp. vanilla extract
Add in dry ingredients, gradually until ingredients are incorporated.
Add in the white chocolate chips and mix just until they are combined. Dough will be sticky.
1 cup white chocolate chips
Cover with plastic wrap and chill cookie dough in the fridge for at least 30 minutes.
Preheat the oven to 375°F.
Line 2 baking sheets with parchment paper or silicone baking mats.
Measure out cookies, about 2 Tbsp. in size, and place on baking sheet. (I bake 6 cookies at a time).
Bake in preheated oven for 10-11 minutes or until the edges look cooked but the middles are still soft and puffy. (Cookies will look puffy right when you take them out and the will settle a little bit as they cool).
Let cookies cool for 15-20 minutes on the cookie sheet, then move to a wire rack to cool completely and enjoy! Continue baking remaining cookies, or place remaining cookie dough in the fridge for up to 3 days, or freeze for up to 3 months.