In a microwave-safe bowl, heat the flour in the microwave on HIGH for 30 seconds. Stir and repeat at 15-second intervals until the internal temperature is 160°F (see note).
¾ cup all-purpose flour
Add the cinnamon and whisk until incorporated. Set the flour aside to completely cool.
¼ teaspoon ground cinnamon
In a large mixing bowl, using a hand mixer, cream the peanut butter and butter together until incorporated, about 2 minutes.
¼ cup unsalted butter, ¼ cup creamy peanut butter
Add the sugar and brown sugar and beat for 3 minutes.
¼ cup granulated sugar, ¼ cup dark brown sugar
Add the salt, vanilla, and milk and mix until fully incorporated.
¼ teaspoon kosher salt, 1 teaspoon pure vanilla extract, 1½ tablespoons milk
Add the cooled flour/cinnamon mixture and mix just until the flour is incorporated.
Add the peanut butter chips and stir just until incorporated.
(Optional) Roll the dough into 1-inch balls for an easy on-the-go snack.
½ cup peanut butter baking chips