Preheat your oven to 350°F. Line two standard baking pans with parchment paper or silicone mats and set aside.
In the bowl of a stand mixer fitted with the paddle attachment or in a large bowl if using a handheld mixer, cream the butter and sugar together on medium speed until light and fluffy, about 2-3 minutes.
Turn the mixer down to low and add in the egg and vanilla and mix well.
Add the flour, baking soda, salt and milk until well blended.
Using a cookie scoop or two spoons, scoop up some dough. Roll it in between your clean hands, and if desired, roll it in your sprinkles. Place it on your prepared baking sheet. Repeat with the remaining dough, making sure to place the balls of dough at least 2 inches apart.
Bake in your preheated oven for 5 minutes. Then rotate the pans, from top to bottom and front to back, and bake for another 5 minutes (the cookies will have baked for 10 total minutes).
Remove the cookies from the oven and immediately press an unwrapped strawberry kiss into the center of each cookie. Allow them to cool before serving.
Leftover cookies should be stored in an airtight container at room temperature and will last several days.Source: Kleinworth & Co