Mini Black Velvet Cake

Preheat the oven to 350ºF and prepare three 4-inch or one 6-inch cake pan by spraying the sides with cooking spray and fitting the bottom(s) with a wax paper or parchment paper cake circle.

Mix together the whole milk and vinegar. Set aside for 10-15 minutes, after which the mixture will look slightly curdled (this is the chemical reaction we're looking for!).

Place all of the dry ingredients into the bowl of a stand mixer and stir on low for 30 seconds to fully combine them. Add the vegetable oil, egg, vanilla, and milk mixture and mix on low until just combined. With the mixer still on low, add the hot coffee (or hot water) in a slow stream, then turn the mixer to medium and beat until smooth, about 2 minutes. The batter will be very thin.

Pour the batter into the prepared cake pan(s). If using 4-inch cake pans, bake for 18-22 minutes. If using a 6-inch cake pan bake for 24-28 minutes. The cake is done when it springs back to the touch and a toothpick inserted comes out clean. Cool completely before assembling and decorating.

In a stand mixer fitted with a paddle attachment, whip the butter on medium speed until creamy and light, about 3 minutes. Scrape down the bowl and paddle, then the powdered sugar. Mix on low speed until incorporated. With the mixer in the off position, sift in the black cocoa powder and add the vanilla, milk, and salt. Mix on low until all ingredients are thoroughly combined, about 2 minutes, scraping down the bowl and paddle as needed.

The buttercream will look dark brown at this point, but the color will darken significantly over the next several hours. See the recipe notes for storage instructions if you're not planning on frosting the cake the same day.

If you're in a hurry, you can add about 1 Tbsp of black buttercream into a microwave safe bowl and microwave for 5-10 seconds, until melted but not hot. Add this into the rest of your buttercream and mix it together with your stand mixer on low speed. This will help darken the color faster.

To create the design pictured: once the cake layers have cooled completely, level them to your desired height. Fill and stack the layers with black buttercream, then crumb coat the cake with more black buttercream. Refrigerate the crumb coated cake for 20 minutes to let the frosting firm up.

Use the black buttercream to create a smooth finish on the cake, then refrigerate it for about 20 minutes. Use the rest of the black buttercream to create lambeth piping using Wilton Tip 4B for the large shell borders, Tip 16 for the small shell borders, and Tip 102 for the ruffle garlands. Feel free to use this tutorial as guidance.