Preheat the ovenLine an 8-inch square baking pan with an aluminum foil sling, leaving some to hang over the sides so the bars can easily be removed. Lightly spray the foil with nonstick baking spray; set aside.
In the bowl of a food processor, process the graham crackers until they resemble sand. Add the melted butter and process again to coat the crumbs with the butter. (The mixture should resemble wet sand.) Add the graham mixture to the prepared baking pan. Using a piece of plastic wrap, press the mixture firmly and evenly in the pan. Refrigerate until firm, about 45 minutes..
In a medium microwave-proof bowl, add the chocolate chips, condensed milk , and a pinch of salt. Microwave on high for 1 minute. Stir to combine. Microwave for another 15 seconds and stir until the chocolate chips are completely melted. Stir in the vanilla. The mixture will be thick and fudgy.
Pour the chocolate mixture into the center of the pan over the graham cracker base. Using an offset spatula, gently spread the mixture from the middle to the edges in one motion. Do not spread back and forth. It will cause the chocolate to pull up the graham cracker base. (If necessary, run the spatula under hot water and dry it before spreading more of the chocolate mixture over the graham cracker base.) Once the chocolate has reached all the edges, gently even the top. Sprinkle the candy over the chocolate layer and gently press the pieces into the chocolate.
Refrigerate the bars until they are firm, about 3 hours. To serve, lift the foil from the pan. Slide the chocolate candy car square from the foil onto a cutting board. Cut into 2-inch squares (or larger if you prefer). Eat cold or at room temperature. Store leftovers in an airtight container in the refrigerator. Enjoy!