Lightly grease a 9x13-inch baking dish with nonstick cooking spray or butter. Line it with parchment paper, leaving overhang on two opposite sides. Set aside.

Place a large, heavy-bottomed saucepan over medium heat. Add the butter and melt completely, stirring occasionally.

Add the miniature marshmallows, reduce the heat to low, and stir constantly for 5 to 7 minutes, until fully melted, smooth, glossy, and free of lumps.

Remove the saucepan from the heat. Add the cherry-flavored gelatin powder and stir vigorously until completely dissolved and fully incorporated.

Add the crispy rice cereal and fold until all the cereal is evenly coated with the cherry marshmallow mixture.

Transfer the mixture to the prepared baking dish. Gently press it into an even, firm layer using parchment paper or a lightly greased spatula.

Let the treats cool and set at room temperature for 15 to 20 minutes, or until firm to the touch.

Combine the semi-sweet chocolate chips and shortening in a microwave-safe bowl. Microwave on 50% power in 30-second intervals, stirring thoroughly after each interval, until melted, smooth, glossy, and pourable.

Pour the melted chocolate over the cooled treats and spread it into an even layer.

Refrigerate for 10 to 15 minutes, or until the chocolate is fully set and firm.

Lift the treats from the pan using the parchment paper handles and place them on a cutting board.

Cut into 24 equal-sized squares or bars. Wipe the knife clean between cuts and serve at room temperature.