Line a quarter sheet pan with parchment paper and spray with nonstick spray. Set aside.
In a medium bowl, combine the rice crisps and ⅔ cup of the crushed freeze-dried strawberries. Set aside.
In a medium or large sized saucepan or pot, melt the vegan butter over medium heat. When it’s fully melted, add the marshmallows. Stir with a silicone spatula constantly. The marshmallows will act like they’re not melting but just be patient and keep stirring.
When the marshmallows are almost totally melted, add the vanilla extract and stir it in. When the mixture is completely melted, turn off the heat and add the rice crisps and freeze-dried strawberry mixture. Fold together until combined, then transfer it into the prepared sheet pan.
Work quickly to press it down gently with the spatula or your fingers. Spread it to the edges of the pan and even the top out. Place the remaining ⅓ of the freeze-dried strawberries on top of the rice crispy treats. Gently press the strawberries into the rice crispy top.
Let cool for 45 minutes. Transfer the pan to the fridge for 10 minutes. Remove from the fridge and use the parchment paper to lift the entire rice crispy treat out of the pan. Use a sharp knife to squares and serve!