Mix butter and sugars

• Combine the cold cubed butter with the light brown sugar and granulated sugar.
• Mix just until no large butter chunks remain.

Add eggs and vanilla

• Add 1 whole egg and 2 egg yolks.
• Add the Mexican vanilla and mix to combine.

Combine dry ingredients

• In a separate bowl, combine the all-purpose flour, Dutch-process cocoa powder, baking powder, baking soda, cornstarch, salt and espresso powder.
• Sift the cocoa powder to remove clumps.

Combine wet and dry

• Add the dry ingredients to the mixer in two additions, half at a time.
• Mix just until combined, being careful not to overmix.

Add peanut butter chips

• Fold in the Reese's peanut butter chips.

Shape the cookies

• Separate and shape the dough into 6 oz (170 g) balls.
• Make each ball taller than it is wide.
• Poke a few holes in the top with your fingers so it isn't too smooth.

Freeze overnight

• Place the shaped dough balls in the freezer overnight.

Bake

• Bake the frozen cookie dough at 350°F (175°C) for 20 minutes.