Spray a 9x13 baking dish with non-stick spray and set aside.
In a large saucepan, melt coconut oil over low heat. Add the pumpkin and stir until warm. Mix in vanilla extract, pumpkin spice, and salt. Fold in marshmallows, stirring occasionally until just melted. Remove from heat.
Allow the marshmallow mixture to cool to room temperature then stir in the cereal until completely combined.
Transfer mixture to prepared baking dish and spread out. You don't want to pack the mixture down but gently press to make an even layer. Let set before decorating or cutting into squares.
To decorate, drizzle icing over the top of rice krisipies.