Prepare Your Wreath Base
Line a large baking sheet with parchment paper. If making a large wreath, place a large round bowl (or a small pot turned upside down) in the center to help guide the wreath shape.
If making the small wreaths, you can shape them with your hands easily.
You can also grease your hands or gloves ahead of time—it gets sticky!
Melt the Butter & Marshmallows
In a large Dutch oven or heavy pot, melt the butter over medium-low heat. Add the marshmallows and stir continuously until completely melted and smooth.
Remove from heat and stir in the vanilla extract and green food coloring until evenly tinted.
Add the Rice Krispies
Working quickly, fold in the Rice Krispies cereal until everything is well coated and evenly colored. The mixture should be sticky and vibrant green.
Shape the Wreath
For the large wreath, scoop the mixture onto your prepared baking sheet, forming a large ring around the bowl in the middle. Press gently with greased hands to shape it into an even, thick wreath.
Remove the center bowl and smooth the inside edges.
For the small wreaths, scoop the mixture onto smaller clumps, 8 on a sheet. Then coat hands with butter or cooking spray and shape the wreaths by poking a hole through the middle and shaping them.
Decorate
While the wreath is still warm and sticky, press the red candies around it to resemble berries.
Add sprinkles or edible glitter if desired. If you'd like a bow, shape one from pull-apart licorice and press it gently onto the wreath.
Set & Serve
Allow the wreaths to cool for about 30 minutes, or until firm.
For the large wreath cut into wedges to serve, or let guests pull apart sections.