Unicorn Cookie Bars are filled with sprinkles, they are buttery & chewy and I topped mine with a homemade Marshmallow Buttercream. Cookies & Cups created the Unicorn Bars recipe. Her Buttercream Frosting recipe looks scrumptious too! The bars are good enough to eat on their own but I felt like whipping up some marshmallow for fun.
The bars bake until their edges are set (25-30 minutes) and they do not look done when you pull them from the oven. They will set up as they cool and they are cooked all the way through. The bars are very easy to make and I had to swat away eager hands even before I had them frosted.
For the Marshmallow Buttercream Frosting:
To a fresh batch of marshmallow I added 1 cup powdered sugar, 1 tsp vanilla, and 1 stick (1/2 cup) of softened butter. I dropped a couple of drops of blue & red food coloring into the frosting for a light lavender color (all in my stand mixer.) I then topped off the bars with a few more sprinkles. The frosting is very, very sticky as you spread it but after a couple of hours it is set. I cut into one end of my bars immediately without thinking and had strings of marshmallow everywhere.
It is important to spread the frosting immediately or the marshmallow will become increasingly sticky. After letting the frosting set for 4 hours, I could cut through with no issues and it is delicious!
Unicorn Cookie Bars are simple & satisfying. The bars would pair well with canned frosting, glaze, or a homemade buttercream too. I just have a thing for marshmallow now that I learned how to make my own. I definitely recommend trying this recipe for your next get together or for yourself!