Servings: yield was 40 to 45 cookies

1 3/4 cups all-purpose flour 1 ¾ cups all-purpose flour
1/2 teaspoon Kosher salt ½ teaspoon Kosher salt
1 teaspoon baking soda 1 teaspoon baking soda
1/2 cup butter , softened ½ cup butter , softened
1/2 cup white sugar ½ cup white sugar
1/2 cup peanut butter - I used Skippy Creamy Peanut Butter ½ cup peanut butter - I used Skippy Creamy Peanut Butter
1/2 cup packed brown sugar ½ cup packed brown sugar
1 egg , beaten, room temperature 1 egg , beaten, room temperature
1 teaspoon vanilla extract 1 teaspoon vanilla extract
2 tablespoons milk 2 tablespoons milk
about 40 miniature Reese's peanut butter cups , unwrapped - place in refrigerator about an hour or two before using to make them easier to unwrap. about 40 miniature Reese's peanut butter cups , unwrapped - place in refrigerator about an hour or two before using to make them easier to unwrap.

Preheat oven to 375 degrees F (190 degrees C). Whisk together the flour, salt and baking soda in a medium bowl; set aside.
Cream together the butter, sugar, peanut butter and brown sugar until fluffy. Beat in the egg, vanilla and milk. Add the flour mixture; mix well. Shape into 1 inch balls and place each into a greased mini muffin tin (or use paper liners). I used paper liners.
Bake at 375 degrees for about 9 minutes. First time, I baked 8 minutes. Do not overbake! Remove from oven and immediately press a mini peanut butter cup into each ball. Cool completely in pans and then carefully remove cookies from pan.
4/9/20: bottom of cookie was too brown - try moving rack up one notch from center and/or baking one tray of cookies (24) at a time.
3/30/21: baked 9 min. On center rack - one tray (24) at a time. These were perfect!

Source: Allrecipes: allrecipes.com/recipe/9471/peanut-butter-cup-cookies/  Source: Allrecipes: allrecipes.com/recipe/9471/peanut-butter-cup-cookies/