Try to get an excess moisture out of strawberries by patting with a paper towel after cutting up.
In a large sauce pan, melt butter over medium heat.
Stir in vanilla and mini marshmallows. Stir continuously and allow marshmallows to melt completely.
Once melted, remove from heat and quickly stir in the rice crispy cereal until well combined.
Add diced strawberries and carefully fold into mixture.
In a parchment lined baking dish, spread mixture evenly and press down firmly.
Allow the treats to cool completely then enjoy!