Line an 8x8” pan with parchment or spray with cooking spray. Set aside.
In a large microwave-safe bowl, melt the butter and marshmallow creme in 15-30 second intervals, stirring in between, until smooth.
If coloring treats, add one drop of food coloring for a light color or more for a darker color to the marshmallow/butter mixture. Stir.
Add vanilla and cereal. Stir gently to mix.
If using, add sprinkles to the mixture and stir.
Place mixture into your prepared pan. With damp hands, press the mixture into the pan. Add additional sprinkles on top of the treats.
Let cool on the counter for about 30 minutes.
Once cooled, remove from the pan and cut into 2” squares. Or, take heart-shaped cookie cutters and cut into shapes.
Optional: Melt some vanilla candy coating and place into a piping bag. Drizzle lines across each Rice Krispie treat and add some sprinkles to the top before the candy coating hardens.
Wrap and store on the counter for up to two days or freeze for up to six weeks.