270 grams (2 1/2 cups) non-fat dry powdered milk
255 grams (9 ounces) powdered sugar
105 grams (3.7 ounces) Dutch-process cocoa powder
1 teaspoon fine salt (see Cook's Note)
2 teaspoons cornstarch
1 pinch (or more to taste) ground cayenne pepper, optional
If, like me, you only have kosher salt, simply blend a few tablespoons to a fine dust.