Decorated Swiss Roll

Matcha Swiss Roll with Mascarpone Cream
The Daring Baker's Challenge for October is a Decorated Swiss Roll. I may give it a second shot before it's all said and done, but this was my first attempt. My kid is on a Matcha Roll (LOL) so I thought I'd try that variation. I don't need to do that again. The filling however is about the best thing I've ever stuck in my mouth. 

Decorated Swiss Roll Recipe

Servings: 6-8
Preheat the oven to 340 ˚F. Line 10”x10” square baking pan, or 9”x13” baking pan with parchment paper, and spray with cooking spray generously. Place your stencil (if using) underneath the parchment paper. For a square pan make sure the pattern is in the middle of the pan. For a rectangular pan, make sure the pattern is in the upper third of the rectangle.

I cut and pasted this directly from Korena in the Kitchen's How to post. 

Part A: Egg Yolk Mixture

3 large egg yolks (save the whites for Part C)
35g / 2 Tbsp + 1 tsp caster sugar
60ml / 1/4 cup water
40ml / 2 Tbsp + 2 tsp vegetable oil
5ml / 1 tsp vanilla extract
80g / 4/5 cup cake flour (or 65g / 1/2 cup all purpose flour + 15g / 5 1/2 tsp cornstarch)
pinch salt
On a large bowl with an electric mixer and whisk attachment, beat the egg yolks with the caster sugar on medium-high speed until very pale and thick. Add the water, oil, and vanilla and mix to combine. Sift over the flour and salt and mix to make a smooth batter. Set aside.

Part B: Pattern Mixture

15ml / 1 Tbsp prepared egg yolk mixture from Part A
approx.. 3g / 1 tsp cake flour
food colouring, if desired
1 large egg white
pinch cream of tartar
Place 15ml / 1 Tbsp of the prepared egg yolk mixture from Part A in a small bowl and mix in the cake flour. Divide this mixture into as many small bowls as you need colours – ie, if you need 3 colours for your pattern, divide it between 3 bowls. Tint the mixture in each bowl with the desired food colouring.
In a clean medium bowl, beat the single egg white with an electric mixer and whisk attachment until foamy, then add a pinch of cream of tartar and beat until stiff peaks form. Measure out 45ml / 3 Tbsp of the egg white meringue (keep the rest for Part C) and divide it evenly between the bowls of coloured mixture. Mix to combine.

(If you want more pattern mixture/more colours, double the ingredients in Part B, using another 15ml / 1 Tbsp of the egg yolk mixture. You will likely have enough meringue out of the 1 egg white to accommodate this.)
Scrape each coloured mixture into a piping bag (or parchment paper piping cone, or small zipper-lock bag with the corner snipped off) and pipe your pattern on to the parchment paper in your prepared baking pan. Remember to pipe the pattern in layers with the details in the foreground first. To avoid smudging the pattern, freeze each layer of the pattern until firm before adding the next layer. For example, I piped the seeds and crown of leaves for each strawberry first, froze until firm, then piped the red strawberries, froze again, and finished with the green vines and leaves.Bake the pattern in the preheated 340˚F  for 60-90 seconds, just until set (you don’t want it to colour/brown at all). Set aside on a cooling rack while you finish making the cake batter.

Part C: Meringue

3 large egg whites
½ tsp cream of tartar
30g / 2 Tbsp caster sugar
food colouring, if desired
In a clean large bowl, beat egg whites with an electric mixer and whisk attachment on medium-high speed until foamy. Add cream of tartar and beat until soft peaks form. Gradually add in the caster sugar, a spoonful at a time, until stiff and glossy peaks form. Mix in any remaining egg white from Part B.

If you want to tint the cake batter with food colouring, mix your desired colour into the egg yolk mixture from Part A. OR, if you want to flavour the cake (see suggested Variations at the end of the recipe), mix the flavouring into the egg yolk mixture now.
One third at a time, mix the meringue into the egg yolk mixture from Part A, folding gently with a spatula so as not to deflate the meringue, until the batter is smooth and no streaks of meringue remain.

Pour the batter over the baked pattern in the prepared cake pan and spread evenly. Lift up the baking pan a few inches and drop it onto the counter 2-3 times to dislodge any large air bubbles. Bake in the preheated 340˚F oven for 12-14 minutes, depending on the size of your cake pan, until just set and slightly springy. Try not to let the cake colour/brown much, if at all.
Place a fresh piece of parchment paper on top of the cake and invert it onto a cooling rack. Lift off the pan and stencil and gently peel back the parchment to reveal the baked-in decoration. Place the parchment back on top and allow the cake to cool between the pieces of parchment paper. Make sure the cake is completely cool before filling.

Part D: Simple Syrup

10g / 2 tsp caster sugar
20ml / 4 tsp boiling water
1 ½ tsp liqueur of your choice, optional
In a small bowl, combine the caster sugar and boiling water and mix until the sugar is dissolved. Stir in the liqueur, if desired.

When the cake is completely cool, peel off the parchment paper and turn it over so that the pattern is facing down and horizontal (for a 9”x13” / 23 X 33cm cake, make sure the short edges are at the top and bottom and the pattern is at the top). With a serrated knife, trim the top and bottom edges at an angle and make some very shallow cuts horizontally across the cake, about 1” / 2.5cm apart. This will help with rolling.
With a pastry brush, brush the simple syrup over the cake and let it soak in while you prepare the filling.

Part E: Filling

8 ounces heavy whipping cream
8 ounces mascarpone cheese
.5 cup sugar
.5 teaspoon vanilla. 
Combine all the ingredients in a mixer bowl. Stir slowly at first, then with an watchful eye whip until it increases in volume by twice. It will look like soft whipped cream. Do not overmix or it will break. 

Tightly roll up the cake from the bottom edge, using the parchment paper to help. The 10”x10” / 25 x 25cm square cake will form a complete cylinder around the filling, with the top and bottom edges meeting. For the 9”x13” / 23 x 33cm cake, lift the bottom edge and tuck it over the filling, then continue to roll – there will be a bit of an overlap between top and bottom edges. Once rolled, twist the parchment paper ends like a candy wrapper to secure the cake in a log. Refrigerate for at least 1 hour until the filling is firm.

To serve, unwrap the parchment paper and trim the ends of the cake with a serrated knife. Roll it up in parchment again and re-shape if necessary, then transfer to a plate. Cut slices with a serrated knife, wiping it clean between each cut.


For Cocoa or Matcha-flavoured Cake:
20g / 3 1/2 Tbsp cocoa powder or matcha powder
30ml / 2 Tbsp boiling water
For Coffee-flavoured Cake:
1 tsp instant coffee granules
½ tsp boiling water
Follow the recipe as above but omit the food colouring in Part C. Instead, in Part C, before you add the meringue into the egg yolk mixture, combine the powder of your choice with the hot water and mix it into the egg yolk mixture. Continue with the recipe as above.
For the cocoa and matcha versions, reduce the baking time by 1-2 minutes – these versions will be slightly drier than the plain sponge and you do not want to over-bake them, or they will crack when rolled.