Preheat oven to 350 degrees and grease a mini cupcake pan. (You would need two mini cupcake pans or you can wait until the first batch is completely cooled.)
In a small bowl, sift together the flour, salt and baking soda. Set aside.
In the bowl of an electric mixer, combine butter and sugar, beat on medium-high speed until light and fluffy, 2-3 minutes.
Add eggs, one at a time, mixing well after each addition. Add vanilla extract. Scrape sides and bottom of the bowl.
Reduce speed to low and add flour mixture. Mix until just combined.
Still on low, drop in chopped Reese’s mini cups, mix until just combined.
Take out about 1 tbsp of dough and roll it into a ball less than an inch in size. Flatten it and place it in the cupcake pan cup, forming a cookie cup. Repeat to fill the pan.
Drop a heaping teaspoon of dulce de leche in each cookie cup.
Bake for 9-11 minutes, take out of the oven and let them cool completely before taking them out of the pan or they will break.