Heat a large and deep skillet or medium to large pot over low heat.
Add the butter and heat until melted.
Add the marshmallows and stir occasionally until the marshmallows are melted, approximately 5 minutes.
Remove the pot from the heat. Add the rice cereal and stir to incorporate.
Pour the rice mixture onto a large baking sheet that is lined with a silicone baking mat or parchment paper, and sprayed with nonstick spray.
Use your hands to press the mixture across the baking sheet in an even layer, all the way to the edges and corners.
Let sit until the marshmallow stiffens.
Cut the treats either into rectangles (6 across and 3 pieces tall) or with a gingerbread man cookie cutter.
Melt the chocolate chips in a resealable bag in 30 second intervals until melted.
Cut a tip off the corner of the bag. Squeeze the bag and make the sashes on the treats (top right shoulder to bottom left).
Gently take the white long sprinkles and place them in two rows down each edge of the sash.
Repeat with remaining treats. Store in an airtight container for up to 4 days.
I like to use the white long jimmie sprinkles, but you can use any shape white sprinkles.9 cups of the rice cereal is approximately one 15.5 ounce box.I like the treats to be softer, which means more marshmallow. If you want the treats firmer with little marshmallow, reduce butter to 4 Tablespoons and marshmallow to 6 cups.