Makes three 6-inch cake rounds or two 8-inch cake

In my opinion, the Wilton 1M piping tip is one of the most
versatile tips out there, so I always keep a few on hand. You can
use them to make my favorite classic rosette cupcake design or
pipe those swirls nice and high on the top of your cakes. You’ll
see it being used in multiple ways throughout this cookbook.
The design I use on my Boston Cream Pie Cake is super easy to
execute, and it will cover up any flaws on the side of the cake
you’d like to hide. The ruffles of chocolate are hard to resist,
and underneath is a soft vanilla cake and an easy-to-whip-up
french vanilla pudding! You could serve this with a drizzle of
dark chocolate for that classic Boston cream pie ganache


  • ¾ cup buttermilk
  • ⅔ cup sour cream
  • 1 Tbsp. vanilla
  • 4 egg whites
  • ⅓ cup vegetable oil
  • 1 box vanilla cake mix


  • 1 (3.4-oz.) package JELL-O instant french vanilla pudding mix
  • 1½ cups milk


  • 1 cup semisweet chocolate chips
  • 1 cup heavy cream
  • 1 cup (2 sticks) unsalted butter
  • 1 Tbsp. vanilla
  • pinch of salt
  • ½ cup cocoa powder
  • 6 cups powdered sugar, sifted

Vanilla Cake

  1. Preheat the oven to 325 degrees. Prep cake rounds with a
    wipe of shortening and dust of flour. Set aside.
  2. In a medium bowl, whisk together the buttermilk, sour
    cream, vanilla, egg whites, and vegetable oil until
    combined. Sift in cake mix and stir until just combined.
    Don’t overmix!
  3. Divide batter between prepared cake rounds and bake for
    25–27 minutes until center is baked through—don’t
    overbake! Remove from oven, let cool in pan for 5 minutes,
    then flip out onto a cooling rack until room temperature.

Vanilla Pudding Filling

  1. In a medium bowl, stir together the cold milk and pudding
    mix until pudding slightly thickens, about 5 minutes, then
    store in the fridge until you’re ready to assemble the cake.

Chocolate Buttercream

  1. In a medium bowl, stir together chocolate chips and heavy
    cream. Microwave for 30 seconds, then stir until all the
    lumps are gone to make a ganache. Set aside.
  2. In a stand mixer fitted with a paddle attachment, whip up
    butter until it’s light and fluffy. Scrape down the sides of the
  3. Add in vanilla, salt, heavy cream, cocoa, and chocolate
    ganache and mix until thoroughly combined.
  4. Slowly add in powdered sugar, about a half cup at a time.
    Add in more heavy cream if needed for a thinner
    consistency. Whip on high for a minute to create a soft
    buttercream, then on low for 30 seconds to beat out any air


  1. On a cake turntable, tape a 6-inch cardboard round on top
    of an 8-inch cardboard round. Top with a small amount of
    buttercream and spread it around to act like “glue” for
    holding the cake onto the board.
  2. Place on first cake round, add on about a cup of
    buttercream, and spread it flat with an offset cake spatula.
    Pipe a dam around the outer rim of the cake and fill with
    about ½ cup of pudding. Add on next layer of cake and
    repeat with remaining two layers.
  3. Crumb coat the cake, place in the fridge to set for about 10
  4. Frost the top of the cake and create a swirl with a cake
    knife, then tidy up the top edges.
  5. Using a Wilton star tip, pipe on chocolate buttercream in
    horizontal layers on the side of the cake, making a
    continuous up-and-down “s” shape.