Combine dairy-free butter and coconut oil over low heat to prevent separation and ensure even distribution throughout the marshmallows for a smooth, creamy texture.

Briefly toast the rice cereal in a dry pan for 1-2 minutes before mixing to enhance its crispiness and prevent it from becoming soggy when the marshmallows release moisture.

Fold in rainbow sprinkles just before transferring to the pan so the color dyes don't bleed into the mixture, maintaining vibrant, distinct sprinkle colors throughout.

Line your baking pan with parchment paper and lightly brush with coconut oil to prevent sticking and allow you to lift out the entire sheet for cleaner, easier cutting.

Refrigerate for at least 30 minutes (or freeze for 15 minutes) before cutting into squares with an oiled knife to achieve clean edges and prevent the treats from crumbling.