Sift together flour, cocoa powder, corn starch, baking soda, and salt, whisk well. Set aside.
Using a stand mixer with the paddle attachment or with a hand-held mixer beat the butter for a minute. Add brown sugar and granulated sugar and beat for 2-3 minutes. The mixture should be light, fluffy, and creamy. Scrap the bowl from the bottom in between for even mixing.
Now add vanilla extract, food color, and milk, mix well on medium speed until food color is distributed evenly. Add white vinegar and mix for few seconds.
Add flour mixture gradually into the butter mixture and on the low-speed mix until a soft dough is formed. Add white chocolate chips and mix at low speed until just combined. The dough will be sticky.
Cover the dough tightly with plastic wrap and place in the fridge for at least 30 minutes.
Preheat oven to 350° F. Line baking sheet with parchment paper or a silicone mat.
Scoop 1 & ½ tablespoon of dough, roll into a ball, flatten it very slightly, and place it on the baking sheet. Repeat with the reaming dough and keep enough space between cookie balls.
Stick some more chocolate chips on the top of cookie balls if you want to. Bake the cookies for 10-12 minutes.
Remove the tray from the oven and let the cookies cool down on the baking sheet for 3 minutes. Transfer the red velvet cookies to a cooling rack and let them cool completely before serving and storing.