Step 1: Prepare the Pan

1. Line a 9×13-inch baking dish with parchment paper for easy removal.

Step 2: Make the Marshmallow Mixture

2. Melt butter in a large pot over medium-low heat, stirring frequently.
3. Cook until the butter turns golden brown and smells nutty, about 3 to 4 minutes.
4. Stir in marshmallows and cook until melted, about 2 to 3 minutes.
5. Add bourbon (if using) and 1 teaspoon salt; stir until fully combined.
6. Mix in Funfetti cake mix until dissolved; remove pot from heat.

Step 3: Combine the Cereals

7. Stir ½ of the Rice Krispies® cereal and ½ of the Fruity Pebbles® cereal into the marshmallow mixture, mixing well.
8. Add the remaining Rice Krispies® and Fruity Pebbles®, and mix until evenly coated.

Step 4: Transfer and Set

9. Press the mixture firmly and evenly into the prepared baking dish.
10. Sprinkle with a pinch of sea salt for a sweet-salty balance.
11. Let cool completely before slicing into bars.