Mix the egg white, powdered sugar, and flour together. Then add the butter. Dip the tip of a kebab skewer in food coloring and then hold it in the batter while you mix. Add more coloring as required for a more intense color.
Put the mixture in an icing bag and squeeze out spots of dough of different sizes here and there into a baking pan lined with parchment paper.
Beat the eggs and sugar with an electric whisk until they are frothy. Add all the other ingredients, then fold them in carefully with a spatula.
Pour the batter as equally as possible over your pink circles. Carefully fill in any gaps using a spatula. The sponge cake batter is more fluid than the one used for dots, so your brightly-colored spots will hold their shape. Now bake for 10 minutes at 360°F.
As soon as the baking is done, place the sponge cake spotted side down on a dampened dish cloth and roll it up with the cloth forming an intermediate layer. Let the roll cool completely. Only then can you roll it out again. This is how you make sure that the sponge cake won't break when you roll it with the filling inside.
Mix cream cheese, powdered sugar, and vanilla extract into a cream and spread it evenly over the sponge cake. Cut the strawberries into thin slices and place them on the cream filling. Finally, roll the sponge cake back up.
