Cake Batter:

Preheat oven to 350° F / 176° C. Line a quarter sheet rimmed baking tray with parchment and spray generously with nonstick spray.

In a large mixing bowl or the bowl of a stand mixer, whip eggs and granulated sugar on high speed until pale, fluffy, and voluminous, about 3-4 minutes. Mix in the vanilla bean paste.

Portion into 2 bowls. Each should weigh approximately 170-175 grams.

With a fine mesh sieve, sift 85 grams self-rising flour into each portion. Into one portion, add 3-4 drops red gel food coloring.

With a rubber spatula, gently fold the flour into the eggs. Try not to deflate the mixture.

Scoop each color into a separate disposable piping bag.

Pipe batter diagonally across prepared tray, alternating colors to form the classic “peppermint stick” pattern.

Bake in preheated oven for 20 minutes, or until dry to the touch.

Dust a clean tea towel with confectioner’s sugar. Immediately flip cake onto towel and peel away the sponge. Dust the top of the cake with more confectioner’s sugar.

With the shorter side facing you, tightly roll the cake in the towel. Set aside to cool completely, about 1 hour. Meanwhile, prepare the buttercream.

Buttercream:

In a large mixing bowl or the bowl of a stand mixer, whip butter on high speed until light and fluffy.

Add the confectioner’s sugar and cocoa powder in small increments, alternating with the milk and mixing well after each addition. Use a rubber spatula to scrape down the sides of the bowl as needed, until you’ve fully incorporated all of the sugar.

Add the peppermint oil and mix until soft and fluffy, about 3-5 minutes. If necessary, add more confectioner’s sugar or whole milk to adjust the consistency.

Assembly:

Carefully unroll the cake.

With a small stepped palette knife or flexible rubber spatula, spread the buttercream evenly across the surface, allowing a 1-inch border on one of the shorter sides.

With your hands, tightly roll the cake around the buttercream.

Wrap the cake in clingfilm/plastic wrap. Refrigerate at least 8 hours, or overnight.

To serve, carefully peel away the plastic wrap. With a sharp chef’s knife, slice into 9-10 slices.

Store leftover cake in the refrigerator for up to 3 days.