• In a mixing bowl, combine the soft butter and salt. Beat for a moment to combine. Add the condensed milk and beat again to combine. Add the powdered sugar a cup at a time, beating to combine thoroughly. Add the peppermint, taste and adjust as needed. The dough will be mostly crumbs, but should stick together when squeezed into a ball. It should not be sticky at all.
• Remove the dough from the mixer and pull off golf ball size sections. (At this point, you can also wrap the dough tightly and store it in the refrigerator until you are ready to roll them out.) Roll each ball out into a long skinny strip about 1/2" in diameter. Slice the strips into tiny mint-size pieces. I used a pizza cutter to easily roll back and forth and slice them quickly.
• Alternative method (for the impatient): Roll the dough out to approximately 1/4" thick. Use a knife or pizza cutter to slice the dough into 1/2" (or smaller) squares. They might not be as cute or as authentic looking, but it will only take a couple minutes to cut out all of the mints.
• Spread the soft pieces across a baking sheet and allow them to sit at room temperature overnight. You could speed up the process and put them in the refrigerator uncovered. Mine were fine on the counter though. When they have hardened enough to store, transfer the mints to an airtight container. Enjoy!

To Make Chocolate Butter Mints

• Reduce the powdered sugar by the amount of cocoa powder in the recipe. Whisk the cocoa powder into the powdered sugar first, before adding the powdered sugar to the recipe. You can skip this step, but it will take a little longer to combine the cocoa powder into the finished dough.