Rum Rose Cake
For the Cake
Make the cake: Preheat oven to 350 degrees. Butter two 9-by-2-inch cake pans; line with parchment rounds. Butter parchment; dust with flour, tapping out excess. Whisk egg yolks and 1 cup sugar in a heatproof bowl set over (not in) a pan of simmering water until sugar has dissolved and mixture is warm, 3 to 4 minutes. Add vanilla and salt. Remove from heat. With an electric mixer on medium speed, whisk until mixture is pale and thick enough to hold a ribbon on its surface, 3 to 5 minutes. Transfer to a large bowl.Advertisement
In a clean mixer bowl, whisk whites on medium-high speed until soft peaks form. Gradually add remaining 1/2 cup sugar, beating until stiff, glossy peaks form. Fold one third of egg-white mixture into yolk mixture. Fold in remaining egg-white mixture. Fold in flour, then melted butter, until just combined. Divide batter evenly between prepared pans. Bake until a cake tester comes out clean, 25 to 30 minutes. Turn out cakes onto a wire rack to cool.
With a serrated knife, split each in half horizontally. Place bottom layer on a cake stand or platter. Brush top with some syrup; spread with one third of the pastry cream. Repeat with 2 more cake layers, brushing each with syrup and spreading each with one third of the pastry cream. Top with final cake layer; brush with remaining syrup.
Spread a thin layer of buttercream over cake to form a crumb coat; refrigerate until firm, about 30 minutes. Spread a second layer of buttercream over cake, smoothing with an offset spatula.
Tint half of remaining buttercream pink with food coloring. Fit a pastry bag with an oversize open-star tip, such as Wilton #1M. From tip to cuff, fill half the bag with untinted buttercream; add pink buttercream to the other half. Pipe roses onto cake: Hold bag at a 90-degree angle to the cake, and pipe a tight, continuous spiral, decreasing pressure as you release. Serve immediately, or refrigerate, uncovered, up to 2 days; let cake come to room temperature before serving.