Use the extra butter to coat the bottom and sides of the 9 x 13-inch pan. Set aside.
In a large pot, melt the butter on low. Before the butter is completely melted, add the marshmallows. Stir until the marshmallows are melting. Turn off the heat. Continue to stir until the marshmallows are completely melted. Add the vanilla and salt and stir.
Add the peanut butter and stir until thoroughly mixed. Add the cereal and stir until it is coated with the peanut butter.
Place the mixture (spread out) into the buttered pan. Place a waxed or parchment paper over the cereal mixture and press with your hand or a large spoon until it is evenly spread out in the pan. Use the cookie cutter to cut hearts. Press together any leftover mixture and repeat cutting hearts until all of it is used.
Chocolate Coating
Place the white chocolate chips into a microwave-safe bowl. Add 1 or 2 drops of pink food coloring. Melt the chocolate for 30 seconds on high. Stir. Heat for 15-more seconds. Stir. Continue heating in 15-second intervals, stirring between each interval, until the chocolate melts. It is best to stop heating before the chocolate is completely melted and stir until it melts.
Dip the hearts into the melted chocolate, coating only one side. Place the hearts on wax paper and refrigerate them for 5-10 minutes to let them set.
Place the semi-sweet chocolate chips and peanut butter chips into a microwave-safe bowl. Melt for 30 seconds on high. Stir. Heat for 15 more seconds. Stir. Continue heating in 15-second intervals, stirring after each interval until the mixture is melted.
Dip the hearts into the melted chocolate, coating the other side. Place the dipped hearts into the refrigerator for 5-10 minutes to set.
Place the semi-sweet chocolate chips and peanut butter chips into a microwave-safe bowl. Melt for 30 seconds on high. Stir. Heat for 15-more seconds. Stir. Continue heating in 15-second intervals, stirring after each interval until the mixture is melted.
Place the chocolate-peanut butter mixture into a plastic zipper bag. Snip off a small corner of the bag to make a piping hole. Squeeze the bag and move your hand back and forth over a heart to create stripes. Chill for 5 minutes to set.
Place lollipop sticks into the bottom of the hearts.
Notes
Troubleshooting
If your finished bars are too hard, the heat was too high when melting the butter and marshmallows. Be sure to use low heat and remove the butter-marshmallow mixture from the heat before all the marshmallows are melted.
Substitutions
You may substitute large marshmallows for miniature marshmallows. Use the same amount of ounces listed in the recipe.
Thin the Chocolate for Easy Dipping
When melting chocolate for dipping the hearts, add vegetable oil to thin the chocolate if it is too thick. Start with 1 teaspoon and add more as necessary. It is easier to coat them when the chocolate is thinner.