Line an 8x8-inch pan with parchment paper or aluminum foil. If using parchment paper, use binder clips to keep the parchment paper against the sides of the pan. Grease the parchment paper/foil with nonstick cooking spray. If you're using a pan, grease it with nonstick cooking spray.
In a medium saucepan, add in the butter, brown sugar, corn syrup, and sweetened condensed milk. Place it over medium-low heat and stir constantly with a spatula.
Once the mixture comes up to a boil, place a candy thermometer on the side of the pan. Continue stirring constantly so the mixture doesn't burn.
Once the caramel comes up to 245 degrees F, turn off the heat and spoon the caramel into the pan. Let the caramel cool.
In a microwave-safe bowl, place the chocolate and shortening. Microwave for 30-second intervals, stirring after each interval until the chocolate is melted. It took 1 minute to completely melt the chocolate.
Once the caramels are completely cooled, slice the caramels into 35 squares for large caramels or 70 small caramels.
Dip the cooled caramels into the chocolate and tap off the extra chocolate. Place on a piece of parchment paper to let the chocolate solidify and add some decorative sprinkles while the chocolate is still wet.
They can stick together if they're not covered in chocolate, so be careful not to layer them without parchment paper or wax paper between the layers.
Notes
Storage: Store these caramels either in an airtight container slightly spaced apart so they don’t stick together or wrapped in parchment paper. They can be stored at room temperature as long as it’s cool or in the refrigerator for up to a month.Freezing: Wrap the caramels in small parchment paper squares to freeze. Place them in a freezer bag or freezer-safe container in the freezer for up to 3 months. Thaw in the refrigerator overnight.