Start by adding sweetened condensed milk, peppermint extract, and powdered sugar into a large bowl. Mix them together with an electric mixer until you get a thick dough that holds together well. Look for a consistency that's thick but still pliable enough to shape.
Next, line two baking pans with parchment paper or wax paper. This is essential for preventing the patties from sticking and for easy cleanup later. Sprinkle some powdered sugar onto a clean surface, such as a cutting board or countertop, to keep the dough from sticking.
Take the peppermint dough and place it on the powdered sugar-covered surface. Using a rolling pin, roll out the dough until it's about ¼ inch thick. Aim for a uniform thickness to ensure even cutting and a consistent texture.
Using a small round cookie cutter that is approximately 1 inch across, cut out the peppermint patties from the rolled dough. Place the cut patties on the cookie sheet, ensuring they are closely placed but not touching. This helps save space while they chill.
Reroll any leftover dough and repeat the cutting process until all the dough has been used. You'll be amazed at how many patties you can get from this simple recipe!
Once your patties are cut, it's time to refrigerate them. Place the pans of peppermint patties in the refrigerator and chill for about 45 minutes. This helps them firm up and makes dipping in chocolate easier.
After the chilling period, take your chocolate chips and vegetable oil and place them in a microwave-safe bowl. Microwave this mixture in 30-second intervals, stirring in between, until the chocolate is completely melted and smooth. Be careful not to overheat, as chocolate can seize easily!
Remove the chilled peppermint candies from the refrigerator. Using a fork, dip each peppermint patty into the melted chocolate, ensuring it is fully coated. Allow any excess chocolate to drip off before placing it back on the cookie sheet lined with parchment or wax paper.
If desired, sprinkle some holiday sprinkles on top of the chocolate-coated patties before the chocolate sets. This adds a festive flair to your delicious homemade candies!
Finally, place the peppermint candies back in the refrigerator for at least 30 minutes to allow the chocolate to set completely. Once they're ready, enjoy your homemade creations!