Ombré Rosette Cakes for a 17th Birthday Celebration

This year, for my daughter’s 17th birthday, she chose a cake from Bakes That Break the Internet by Kat Buckley—an Ombré Rosette Cake. The original recipe was quite simple and used margarine instead of butter, designed for a smaller tin. Wanting to make a bigger and better version, I went on the hunt for a more substantial recipe and found inspiration in The Baking Bible by Rose Levy Beranbaum. I adapted her White Christmas Peppermint Cake to create an ombré vanilla cake, and since we were expecting a large crowd, I decided to make two cakes to ensure everyone got a slice.

The Cakes

Before diving in, I watched several YouTube tutorials to perfect my technique, and it definitely paid off—these were the straightest cakes I’ve made to date! One key trick I learned was using cake strips to ensure even baking without a domed top. If you’re unfamiliar, cake strips are simply strips of an old tea towel, soaked in water, and wrapped around the cake tin before baking. This helps the batter bake evenly, preventing over-browned edges and a peaked center.

Once baked, I used a ruler and toothpicks to mark and cut each cake into two even halves for a more professional look. Since I was making two cakes, consistency was key to ensuring they both had the same elegant layered effect.

Cake Recipe (for each cake)

Ingredients:

• 6 large egg whites (180g), at room temperature

• Milk (322g)

• Vanilla extract (3 tsp)

• Plain flour (400g)

• Caster sugar (400g)

• Baking powder (2 tbsp)

• Fine sea salt (½ tsp)

• Unsalted butter (227g), at room temperature

Method:

1. Preheat the oven: Place an oven rack in the lower third of the oven and preheat to 350°F/175°C.

2. Mix the liquid ingredients: In a medium bowl, whisk the egg whites, ⅓ cup (79 ml) of the milk, and vanilla until just combined.

3. Prepare the batter: In a stand mixer fitted with the flat beater, mix the flour, sugar, baking powder, and salt on low speed for 30 seconds. Add the butter and the remaining milk, then beat on low until moistened. Increase to medium speed and beat for 1½ minutes.

4. Incorporate the egg mixture: Gradually add the egg mixture in three parts, beating for 20 seconds after each addition. Scrape down the sides of the bowl.

5. Bake: Pour the batter into the prepared tin bake for 50 minutes, or until golden brown and a cake tester comes out clean.

6. Cool and unmold: Let the cakes cool in the tin for 10 minutes, then invert onto a wire rack to cool completely upside down—this helps flatten any domed tops.

The Buttercream

While Kat Buckley’s original buttercream recipe was simple, using just butter, icing sugar, vanilla extract, and milk, I wanted something richer and more stable for the intricate rosette piping. I found the perfect solution in Rose Levy Beranbaum’s Raspberry Mousseline, which isn’t exactly an Italian meringue buttercream but has a similar silky texture.

Interestingly, I wondered why Beranbaum called it mousseline, since most sources define mousseline as pastry cream mixed with butter. However, in this case, it’s closer to an Italian meringue buttercream, made by whipping hot sugar syrup into egg whites and incorporating butter for a light and airy consistency. The result is a luxurious, velvety frosting that pipes beautifully and holds up well at room temperature.

I used the buttercream without the raspberry purée for the crumb coat and in between the layers, keeping it smooth and light. Just before piping the rosettes, I mixed in the raspberry purée to achieve the perfect ombré effect.

Raspberry Mousseline Buttercream (enough for two cakes)

Ingredients:

• 1020g unsalted butter, at room temperature

• 9 large egg whites

• 1.5 tbsp apple cider vinegar

• 463.5g granulated sugar

• 165g water

• 142.5g raspberry sauce (prepared earlier)

Method:

1. Prepare the butter: Beat the butter in a stand mixer on medium-high speed until creamy. Set aside.

2. Make the sugar syrup: Heat water and sugar in a saucepan until it reaches 248-250°F/120°C.

3. Whip the egg whites: In an other bowl beat with vinegar until soft peaks form, then slowly pour in the hot sugar syrup in three parts. whipping for a minute after each addition. Continue beating until the mixture cools to room temperature, or cool the meringue in the fridge for 10 minutes.

4. Combine: Gradually add the meringue to the creamed butter and beat until smooth.

5. Final step: Reserve some buttercream for layering and crumb-coating. Before decorating, mix in the raspberry purée for the ombré effect.

Assembling the Cakes

Once all the components were ready, I stacked the layers of both cakes with the plain buttercream in between and applied a thin crumb coat. The crumb coat helps seal in any loose crumbs and provides a smooth base for the final decoration.

Tips for Assembling:

• Use a turntable for smooth frosting application.

• Chill the crumb-coated cakes for at least 30 minutes before final decoration.

• When piping the rosettes, I used toothpicks to mark the center of the cake. Starting from the middle, I piped the first rosette and then worked outward in a circular pattern to create an even and balanced design. This helped ensure the rosettes were symmetrical and evenly spaced.

Final Thoughts

Making two cakes was definitely an effort, but seeing my daughter’s face light up made it all worthwhile. The balance of soft vanilla cake with the light, fruity buttercream made for a delicious and beautiful celebration.

If you’re looking for an impressive cake for a special occasion, I highly recommend giving this one a try. The extra effort in achieving even layers and mastering a stable buttercream makes all the difference.