Step 1

Heat the oven to 450F.

Step 2

Line a [17X12" jelly/sheet pan | http://amzn.to/1oQbGEY ] with [parchment paper | http://amzn.to/1BfGrsy] . Set aside.

Step 3

In a mixing bowl add the 2 eggs, 3 egg yolks and 1/2 cup sugar. With the paddle attachment on, beat on medium to high speed around 5 minutes until pale in color and thickened. Add the vanilla extract and beat few more seconds.

Step 4

Sift the flour and the cornstarch over the egg yolks mixture and with a spatula gently fold it in.

Step 5

Fold in the batter bits as well.

Step 6

In a separate grease-free bowl, add the 2 egg whites and 1 tablespoon of sugar. With a whisk, whip until firm peaks form.

Step 7

With the spatula, fold the whipped egg whites into the egg yolks mixture.

Step 8

Pour the cake batter into the prepared pan, spread it evenly and bake for 6-7 minutes until golden brown and, when touched, it springs back.

Step 9

As soon as you remove the cake from the oven sprinkle with powder sugar and then invert the cake onto a clean dish towel. Remove the parchment paper, sprinkle with more powder sugar, and roll up the cake with the towel. Place on a wire rack to cool

Step 10

!Vanilla buttercream

Step 11

In a clean bowl add the butter. With the whisk attached on to the the mixer whip the butter for 2-3 minutes on medium to high speed.

Step 12

Lower the speed and slowly add the sugar, 1/2 cup at a time.

Step 13

When all the sugar is incorporated increase the speed and whip for 2 more minutes.

Step 14

Add few drops of heavy cream until it reaches the consistency you desire.

Step 15

With a spatula fold in the sprinkles.

Step 16

Gently unroll the cake and spread the buttercream evenly all over it.

Step 17

Roll it again and place in the fridge for a couple of hours.

Step 18

To decorate, melt the white chocolate in double boiler or microwave and pour it over the cake. Add Add more sprinkles (optional)

Step 19

Let the chocolate settle for few minutes and slice the cake.