Preheat the oven to 425°F (NOT A TYPO). Line 2 to 3 baking sheets with parchment paper and set aside.
Whisk together the cake flour, all-purpose flour, malted milk powder, cornstarch, salt, and baking soda in a medium bowl. Set aside.
1¾ cups cake flour, 2 cups all-purpose flour, 1 tablespoon corn starch, 1½ teaspoons salt, ½ teaspoons baking soda, 3 tablespoons malted milk powder
In a stand mixer fitted with a paddle attachment, cream together the cold butter and sugars. Mix at medium-high speed until smooth, about 3 to 4 minutes, scraping down the sides of the bowl about every minute.
1¼ cups cold unsalted butter, 1⅓ cups light brown sugar, ½ cup granulated sugar
Once combined add in the eggs one at a time followed by the egg yolks. Then mix in the vanilla extract.
2 large eggs, 3 additional large egg yolks, 1 tablespoon vanilla extract
Once smooth, add the flour mixture a little at a time until smooth.
Add in the chopped chocolate and peanut butter chips. Mix just until combined.
9 ounces chocolate covered peanut butter pretzel nuggets, 8 ounces semi-sweet chocolate, 1 cup peanut butter chips
Roughly chop the chocolate covered pretzels and fold them into the mixture by mixing for about 5 seconds on the stir setting or using a rubber spatula.
Weigh each dough ball out to 5.8 oz and place on a parchment-lined baking sheet and refrigerate for 15 minutes. If baking at the higher temperature, you can probably bake 6 cookies on a hald-sheet pan. If baking at the lower temperature mentioned in the notes, you'll only be able to bake 4 at a time.
While the first batch chills, prepare the second batch on another cookie sheet and place it in to chill when you take the first batch out to bake.
Bake for 9 to 11 minutes.
Allow them to set on the pan for a couple of minutes before transferring to a wire rack to cool completely.
Once cooled, melt the chocolate melting wafers in a microwave-safe bowl at 30-second intervals, stirring between each one, until fully melted.
10 ounces chocolate melting wafers
Spoon melted chocolate over the top of the cooled cookies, then sprinkle with chopped peanuts and top with a chocolate-covered peanut butter pretzel. Let harden at room temperature or pop in the refridgerator for 10 to 15 minutes.
3 tablespoons chopped peanuts, 9 ounces chocolate covered peanut butter pretzel nuggets