Instructions

1. Preheat oven to 350F. Grease and lightly flour three 9-inch cake pans.
2. In large bowl, whisk flour, baking powder, baking soda and salt together. Set aside.
3. Using handheld mixer or stand mixer fitted with paddle attachment, beat butter and sugar together on high speed until smooth and creamy, about 3 minutes. Scrape sides and bottom of bowl with rubber spatula as needed.
4. On medium-high speed, add 1 egg at a time, beating well after each addition. Beat in vanilla extract. Scrape sides and bottom of bowl with rubber spatula as needed.
5. With mixer on low speed, add dry ingredients in three additions alternating with buttermilk, beginning and ending with dry ingredients, and mixing each addition just until incorporated.
6. Add 5 drops red food coloring to turn batter pink.  Do not overmix this batter. It should be smooth, velvety and slightly thick.
7. Divide batter evenly into prepared cake pans. (Each layer will be about 2-2/3 cups.) For extra precision, use kitchen scale and weigh filled cake pans (about 1 pound 6 ounces each.)
8. Bake for 25–26 minutes or until cakes are baked through. To test for doneness, insert toothpick into center of cake. If it comes out clean, it is done.
9. Allow cakes to cool completely in pans set on wire rack. Cakes must be completely cool before frosting and assembling.
10. In large bowl, using handheld mixer or stand mixer fitted with paddle attachment, beat butter on medium speed until creamy, about 2 minutes. With mixer on low, add 5-1/2 cups confectioners' sugar, 5 tablespoons heavy cream, vanilla extract and salt.
11. Once moistened, increase mixer to high speed and beat for 3 minutes. Add 1/2 cup more confectioners' sugar if frosting is too thin. Add 1 tablespoon cream if frosting is too thick. Add pinch more salt if frosting is too sweet. Yield: about 4-1/2 cups frosting.
12. To assemble and decorate cake: Using large serrated knife or cake slicer, slice thin layer off tops of cakes to create flat surface. (Save these cake scraps to crumble over ice cream.)
13. Place 1 cake layer on cake stand, turntable or serving plate. Spread 1-1/2 cups of frosting evenly on top.
14. Top with another cake layer and evenly cover top with 1-1/2 cups of frosting.
15. Top with third cake layer. Spread remaining frosting on top and all around sides using an icing spatula. For light layer of frosting, use bench scraper to smooth out frosting on sides of cake.
16. Dust flat surface with powdered sugar. Knead small amount of white fondant until smooth. Using rolling pin, roll out fondant until 1/4-inch thick. Place 1 cookie cutter in shape of leaf (ear) on dough.  Press out two pieces. Set aside.
17. Wearing gloves (to prevent staining on skin), color small amount of white fondant with pink food coloring.  Cut out two smaller sized leaves (ears) with cookie cutter, making two smaller pieces.
18. Spread bottom of smaller leaf (ear) with a bit of reserved buttercream. Press in center of larger leaf.  Repeat process, turning other leaves in opposite direction to resemble unicorn ears.
19. Add black food coloring to very small portion of fondant.  Roll out very thinly to create two lines, and four eyelashes.
20. Dab frosting all over pointed ice-cream cone.  Place edible sparkly sugar on plate and roll ice cream cone in sugar.
21.  Place cone on center of cake top as a horn.
22.  Place ears next to horn, one on each side.
23.  Add generous amount of assorted sprinkles (we used Fancy Sprinkles) to top of cake.
24. Add candy sour straps to top and sides of cake, placing straps twisted and flowing from top to bottom of cake.  Form curly mane, pushing through buttercream frosting to secure.
25. Place 1 line of black fondant on cake to make eye, then add two smaller pieces above eye to create eyelashes.
26. Add generous amount of assorted sprinkles in various sizes around base of cake, extending up about 2 inches.
27. Refrigerate cake for 2 to 3 hours or up to 1 day before slicing and serving. If chilling for more than a few hours, loosely cover with plastic wrap after 1 hour of refrigeration. Cover and store leftover cake at room temperature for 1 to 2 days or in refrigerator for up to 1 week.