For the rose cake, whisk together eggs, baking powder, sugar and butter until well blended. Sift in the flour and stir in. Pour the batter into a rather smaller mold (20 cm) or make double the amount of batter so that the cake gains height.
Oil the pan beforehand and dust with a little flour. Bake for about 30 minutes at 190°C in a preheated oven. Allow to cool well and remove from the pan.
For the ganache, heat the whipped cream (do not boil!) and add the white chocolate piece by piece. Melt while stirring constantly until a homogeneous mass is formed. Now stir in the food coloring (it is better to use a little darker than desired, because the color will become even lighter when whipped).
The ganache must now cool at room temperature. As soon as it has cooled down, you can also put the ganache in the refrigerator. Once the ganache is thoroughly chilled, mix it up with a hand mixer.
It may take 5-10 minutes for the ganache to set. Place ganache in a piping bag fitted with a star nozzle and pipe rose petals all over the cake. Serve the rose cake.