Heat treat your flour in one of two ways.Microwave method: Add flour to a microwave-safe bowl and microwave on high for 30 seconds. Stir a couple of times. Repeat two more times for a total of 90 seconds.Oven method: Preheat oven to 300°F. Spread the flour out on a baking sheet and bake on the bottom rack for 5 minutes.
¾ cup all-purpose flour
In a large mixing bowl, cream butter and sugar together with a hand mixer until aerated and combined (2-3 minutes).
3 tablespoons unsalted butter, ½ cup granulated sugar
Once the flour has come back down to room temperature after heat treating, add it to the butter and sugar along with the vanilla extract, milk, and salt. Use your hand mixer to combine.
½ teaspoon vanilla extract, 2 tablespoons milk, ½ teaspoon table salt
Use a spatula to fold in rainbow sprinkles. Serve with a spoon or use clean hands to roll the dough into bite-sized balls—about 1 teaspoon of dough in each.
Notes
Make sure your flour has cooled before adding it to your butter and sugar mixture.