1/2 cup white chocolate chips, plus about a cup more reserved for topping
Directions:
In a medium bowl, stir together flour, cocoa powder, cornstarch, baking soda, and salt.
In a stand mixer bowl, beat together butter, shortening, and sugar on medium speed for about 3 minutes, until fluffy.
Add egg and yolk and mix until just combined.
Add vinegar, vanilla, and food coloring. Mix until combined.
Slowly add in the dry ingredients and mix until just combined. Do not overmix! Stir in 1/2 cup white chocolate chips.
Scoop dough with a cookie scooper and roll into balls (about golf ball-sized) that are built taller than they are wide. Place onto a parchment paper or silicone mat lined baking sheet.
Press about 4 or 5 more white chocolate chips on top of each ball of dough, but do not flatten them.
Bake cookies in a preheated 375-degree oven for about 8 to 9 minutes. Cool for 5 minutes on the baking sheet before removing to a wire rack to cool completely.