Before you start, make sure to heat-treat your flour so it’s safe to eat. Microwave it in a microwave-safe bowl in 30-second intervals, stirring between each, until it reaches 165°F. Optional: You can also bake it on a parchment-lined baking sheet at 350°F for 5–7 minutes if you prefer. Let it cool before using.

In a large mixing bowl, cream together butter, sugar and brown sugar.

Mix in a splash of the milk (not all of it yet), vanilla extract, and salt until the mixture looks creamy and smooth. Scrape down the sides of the bowl so everything is fully combined.

Once the flour is completely cool, gradually add it to the bowl.  Mix on low or stir by hand until you get a thick, scoopable dough with no dry patches.  If your mixture is too try, add in another splash of milk until you get the texture you want.

Gently fold in the rainbow sprinkles.

Scoop out portions of dough (about 1 tablespoon each) and roll them into smooth balls between your palms, or use a small cookie scoop for uniform sizes. Place each dough ball in a mini cupcake liner to make storing and serving easy. Arrange them on a parchment-lined baking sheet or plate.

Refrigerate for 20 to 30 minutes so the edible cookie dough firms up.