Prep all your ingredients before starting the recipe because this recipe moves fast.
Line a 9x13 pan with parchment paper. Spray with cooking spray. Set aside. This will help with cutting and removing the squares from the pan later.
In a saucepan, melt butter over low heat. Add the marshmallows, then stir consistently until melted.*
Remove from the heat. Stir in the guava marmalade with the melted marshmallows until the mixture turns a pinkish-red color.
Carefully mix in the rice cereal, cubes of guava paste, and crumbled Maria cookies with the melted marshmallows. Stir until all is well combined.
Transfer the mixture into the pan, gently pressing down into an even layer. You can spray a spatula with cooking spray (or your hands) to press down the mixture.
After 30 minutes once the mixture has cooled completely at room temperature, cut into squares. Enjoy!
Notes
*TIP: You can also microwave the butter and marshmallows for 2 minutes on HIGH, then stir until melted.Storage: After 2 days at room temperature, wrap each square in plastic wrap and freeze them in a freezer bag. Thaw at room temperature or pop one in the microwave unwrapped for 10 seconds.