You know that saying, that how something healthy can't possibly taste good? I refute that. And this cake is here to prove it.
The cake is a sponge cake with very little added fat, filled with strawberry jam (fruits!) and a chocolate mousse made with tofu. Yes, tofu! Okay, maybe this isn't totally healthy but what I'm trying to say here is that its totally delicious. P.S. If you're wondering what's up with the tofu, seeing how I had used it here before, and now using it again, I can tell you frankly that I have no idea. I saw an unused pack in the fridge and I felt like transforming it into something sweet? I'm weird.
Oh and don't forget the chocolate peanut butter rice krispie bark. It has good-for-you peanut butter, being packed with protein and all, rice krispies for the all-important carbs and chocolate for a healthy state of mental well-being.
You will definitely notice that the mousse is not as heavy as its traditional counterparts. Well good, so eat up. The only finicky thing about it is that it sets very softly- even after chilling for a good 36 hours its consistency is that of softly whipped cream. In other words, its loose. This made frosting the outsides of the cake roll scary at first- the mousse applied to the top part of the cake slowly made its descent to the bottom. However, the problem is easy to solve. A quick chill in the fridge until the applied mousse is firm enough to be manipulated again, then use your spatula to sweep the mousse that has pooled at the bottom upwards.
I deviated from the usual strawberry jam by adding brown sugar and balsamic vinegar in replacement of white sugar and lemon juice respectively. I wish I could say that this decision was premeditated, but I would be lying. Okay maybe the brown sugar addition was, but I used the balsamic vinegar simply because it was 10 pm at night and I didn't want to be slicing and juicing a lemon for less than 1 tsp of juice. Anyway, the unique taste of the resulting jam, as part of the whole cake, is unfortunately hard to discern. I did manage to pick up a deeper richer flavour that would not be achieved with just plain sugar and lemon juice though. (By the way, the colour of this jam is beautiful. Pomegranate red, dark and glistening.)
The bark was actually a last minute addition, because the sides looked too plain, but I don't feel that this merely served a decorative purpose. The holy trinity (in my opinion) of flavours came together harmoniously in this cake- chocolate, peanut butter and strawberry. Don't miss it.
Vertical Chocolate Strawberry Swiss Roll Cake
For the strawberry jam:
1/4 pound strawberries
2 tbsp brown sugar
1/4 to 1/2 tsp balsamic vinegar
2 tsp cornstarch dissolved in 2 tsp water
For the milk chocolate mousse:
60g milk chocolate chips, melted and cooled
180g silken tofu
2 tbsp unsweetened cocoa powder, sifted
For the cake:
10g unsweetened cocoa powder, sifted, plus extra for dusting
20ml hot water
30g egg yolks (about 1 1/2 medium eggs)
22g + 30g sugar, separated
37g cake flour, sifted
60g egg whites (about 1 1/2 medium eggs)
For the chocolate peanut butter rice krispie bark:
1/4 cup peanut butter
1/2 tbsp melted butter
1/4 cup icing sugar, sifted
pinch of salt
1/2 cup rice krispies
milk chocolate chips, as needed, melted and cooled
sprinkles, as needed
sea salt, as needed
For the strawberry jam: Place the strawberries in a medium saucepan. Place the saucepan on medium heat and use a wooden spoon to crush the strawberries. Cook the strawberries until they have released their juices and reduced slightly. Add the brown sugar and balsamic vinegar and stir to incorporate. Cook for a while more until the mixture becomes a bit more concentrated then stir in the cornstarch slurry. Let it boil, stirring constantly, until it has thickened. Pour the jam into a bowl to cool before refrigerating.
For the chocolate mousse: Combine all the ingredients in a blender and blend until combined. Pour mixture into a bowl and refrigerate overnight.
For the cake: Preheat oven to 350F. Line a 9 inch square baking pan.
Dissolve the cocoa powder into the hot water. Set aside to cool.
Whisk the egg yolks and 22g sugar together until pale. Whisk in the chocolate mixture, then the oil and milk until combined. Whisk in the flour until just incorporated.
Whisk the egg whites until they reach soft peaks. Gradually add the 30g sugar, whisking constantly, until the egg whites have formed stiff peaks. Whisk 1/3 of the egg whites into the chocolate mixture to lighten, then fold in the rest of the egg whites.
Pour the batter into the prepared pan and bake for 10 to 12 minutes or until an inserted skewer comes out clean. Cool in the pan completely.
For the chocolate peanut butter rice krispie bark: Cream the peanut butter, melted butter, icing sugar and salt together until combined. Stir in the rice krispies. Spread the mixture onto a silicon baking mat or a lined sheet pan as thinly as you can. Spread the melted chocolate on top then sprinkle over the sprinkles and sea salt. Refrigerate until firm, at least 1 hour. (The amount of chocolate you need depends on your surface area- how thinly you spread the rice krispies mixture out.) Break into large pieces.
Assembly: Sift some cocoa powder over the surface of the cake. Turn the cake out onto a flat area and remove the parchment. Slice the cake into half and spread the strawberry jam thinly across. Spread a thin layer of chocolate mousse on top. You don't want to overdo it because if you apply too much, most of it will just ooze out. Roll one half of the cake up and stand it vertically on a cake board. Wrap the second half around the first roll. Slice away the ends of the second roll to make the cake as circular as possible. Refrigerate the cake for at least an hour to set the mousse. Then, frost the outsides of the cake with the remaining mousse. (You may not use all of it.) If the mousse is too soft, most of it will slide down and puddle at the bottom of the cake. If that happens, refrigerate the cake until the mousse is firm then use your spatula to spread the mousse upwards. Chill the cake again for at least 6 hours. Lastly, decorate with the rice krispie bark pieces.