Step 1: Mix the Butter Base
Start by placing softened butter in a large mixing bowl. Use an electric mixer to beat the butter until creamy and smooth, which should take about 2 minutes. Add the sweetened condensed milk and peppermint extract. Blend until the mixture is smooth and well-combined.

Step 2: Combine Ingredients
Gradually add the powdered sugar and salt into the butter mixture. Stir slowly, allowing the powdered sugar to absorb before adding more. The dough should be thick and slightly sticky. If it feels too sticky, add a little more powdered sugar until you reach the desired consistency.

Step 3: Divide and Color the Dough
Divide the dough into two equal portions. Leave one portion white, and use red gel food coloring to tint the other half. Add a small amount of coloring at a time until you achieve the desired festive red shade. Knead the coloring into the dough until fully incorporated.

Step 4: Shape the Mints
Roll each portion of dough into a long, thin rope about 1/2 inch thick. Lay the red and white ropes side by side and twist them together to create a candy cane effect. Slice the twisted ropes into small pieces, forming cubes or rounds, as preferred.

Step 5: Dry the Mints
Line a baking sheet with parchment paper and arrange the shaped mints in a single layer. Allow the mints to dry for at least 6 hours or, preferably, overnight. This step ensures the mints will have the right texture.

Step 6: Add the Finishing Touches
For extra sparkle, roll each mint in granulated sugar. This step is optional but adds a festive and decorative touch to your butter mints, making them look even more like holiday treats.

Step 7: Store Properly
Transfer the mints to an airtight container once they are fully dry. Keep them at room temperature to maintain their soft texture.