• Preheat your oven to 350F. Grease and line 3 6-inch cake pans with parchment paper.
• In the bowl of a stand mixer, fitted with the paddle attachment, beat the softened butter until smooth. Add in sugar and continue mixing. Add vanilla and eggs, one at a time, and mix until well combined.
• In a separate bowl, whisk together flour, salt, baking powder and baking soda.
• Alternate mixing in the dry ingredients and the buttermilk, beginning and ending with the dry ingredients. Do not overmix.
• For the Chocolate Cake Layers
• Using a kitchen scale, split the batter amongst 3 separate bowls. Add the melted and cooled dark chocolate to one bowl, and repeat with the milk and white chocolate adding it to the remaining 2 bowls.
• Transfer to prepared cake pans and smooth out the tops. Bake for 25-30 minutes, or until toothpick inserted in center comes out clean.

Assemble your Chocolate Ombre Cake:

• To assemble the cake, place the dark chocolate layer on a cake stand (or turntable, if using). Spread the chocolate icing on top of the cake. Repeat with the following layers, finishing with the white chocolate layer on top and warm vanilla icing.
• To make an ombre effect, place the remaining chocolate icing in one bowl and the warm vanilla in a separate bowl. Add a scoop on each icing into a third bowl and mix to create a lighter brown color.
• Fill 3 piping bags with each icing and cut off the tips. Start with the first color (vanilla icing) and pipe it on, going around the cake twice. Repeat with the two remaining icing colors; first the lighter chocolate, and finish with the darker chocolate.
• Using a cake scrapper, smooth out the sides cleaning the scrapper as you go. Push in against the cake to get rid of any air bubbles and excess icing.
• Go around the cake until all the sides are completely smooth.
• Smooth out the top of the cake scrapping gently and removing any excess off.
• Decorate with Vanilla & Chocolate Jimmies Sprinkles.