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Unicorn bars on a white plate.

Unicorn Bars

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  • Author: Sandra Flegg
  • Total Time: 55 minutes
  • Yield: 12 to 16 servings


Brownie Layer

1 cup butter, softened at room temperature

10 ounces white chocolate, chopped

1 and 1/4 cups granulated sugar

4 large eggs

2 cups all purpose flour

1 Tablespoon vanilla

1/2 teaspoon salt

1/2 cup rainbow sprinkles

Buttercream Frosting

1 cup butter, softened at room temperature

4 cups powdered sugar

3 Tablespoons heavy cream

3 drops food coloring, red & blue

1/2 cup assorted rainbow sprinkles for decorating


  1. Grease a 13 x 9-inch baking dish or line with parchment paper. 
  2. Preheat oven to 325°F.
  3. Place butter and chopped white chocolate in a saucepan. Melt over low heat, stirring occasionally.
  4. Let cool for 10 minutes. The butter and the white chocolate may appear to separate. That is normal and they will blend together when you add the sugar later on in the recipe. 
  5. Add in granulated sugar and stir until well-combined.
  6. Add in eggs, one at a time, stirring well after each one is added.
  7. Stir in all-purpose flour, salt and vanilla. Mix until well-combined.
  8. Stir in the sprinkles. I like to use a mixture of the flat ones and the small and medium round ball sprinkles. 
  9. Bake in 325°F oven for 30 to 35 minutes until cake tester comes out clean.
  10. Cool completely on wire rack before frosting. 
  11. For frosting: In bowl from stand mixer, or mixing bowl with hand mixer, beat butter for two minutes. 
  12. Slowly, add in powdered sugar, alternating with cream, adding 1 to 2 tbsp. of cream at a time. 
  13. Add in vanilla and beat until smooth. (About 2 minutes). 
  14. When you’re making the icing, you may need to add a bit more powdered sugar or cream to achieve a nice spreadable consistency. 
  15. Next, set aside 1/2 cup of frosting and tint with a few drops of blue food colouring, starting with one drop and adding more if needed to achieve a light turquoise-bluish colour. 
  16. Take half of the blue icing and place in a separate bowl. Add one drop of red food colouring (to the blue icing) to make purple icing. You may need to add a bit more colouring to achieve the desired shade of purple. 
  17. Frost cooled bars completely with remaining white icing. 
  18. Place blue and purple icing in separate decorator bags. I like to use the disposable ones and no tip. I simply fill with the icing and snip off the end to the desired thickness. 
  19. Pipe diagonal blue lines across the blondies.  Pipe purple lines diagonally across going the opposite direct to form diamond pattern. Top with sprinkles and enjoy!


  • store bars in a single layer using an airtight container for 3-5 days in the refrigerator.
  • freeze unicorn bars in a single layer wrapped in parchment paper, using a freezer-safe container for up to 1 – 2months.
  • Prep Time: 20 minutes
  • Cook Time: 35 minutes
  • Category: Dessert
  • Method: Oven Baked
  • Cuisine: American