Combine butter, corn syrup, extract and powdered sugar in a mixing bowl. Mix with an electric mixer for about 3 minutes, until ingredients are well combined and are holding together.
Remove dough from bowl and break off about 2 teaspoon-sized sections. Roll into a ball and gently flatten with your hands. Put patties down on a pan lined with wax or parchment paper. Once all patties are made, place pan in the freezer for 10-15 minutes.
Melt chocolate in microwave for 1 minute 20 seconds. Let sit for an additional minute in the microwave. Remove and gently stir. Remove peppermint patties from freezer. Use a fork or a handy Winton Dipping tool like I did to dip each patty in the chocolate, flip to coat the other side, then tap to remove any excess. Transfer chocolate coated patties to wax paper to cool. Top with chocolate jimmies if you’d like.
Store in an airtight container, refrigerate if preferred but it’s not necessary. Yields 40 mints.