Preheat the oven to 450 degrees. Line a 12x17 or similar sized pan with sides with parchment or foil. Coat with non-stick spray. Set aside.
Combine the 2 whole eggs, 3 egg yolks and ½ c sugar. Use the paddle attachment to mix on medium speed for about 5 minutes. The mix should be a pale yellow and slightly thickened
Add 1 teaspoon vanilla and mix well.
Add in ⅓ cup flour and 3 tablespoon corn starch. Use a spatula to fold in the dry ingredients, just until combined.
In another bowl, combine the 2 egg whites and 1 tablespoon of sugar. With the whisk attachment, whip the egg mixture on high for about 2-3 minutes or until stiff peaks.
Add the whipped egg whites to the other bowl with the cake batter. Use the spatula to gently fold the two mixtures together just until combined.
Pour the batter into your prepared pan and spread evenly.
Bake in the preheated oven for 8-10 minutes or until a light golden brown and the center is set.
Allow to cool for about 5-10 minutes.
Sprinkle the cake with a thin layer of powdered sugar. Top with a piece of parchment paper that extends over the ends of the cake by at least two inches.
Invert the cake so that it is on the new parchment. Carefully remove the pan and the used parchment/foil, discard
Sprinkle with another light layer of powdered sugar. Roll the cake, starting on a short end, so that the parchment is rolled with the cake to separate the layers.
Allow to cool completely.
Combine 1 cup butter, 3 cup powdered sugar and 1 teaspoon vanilla.
Mix on low speed until combined and then bump up the speed to medium and whip for another 2-3 minutes or until smooth and fluffy.
Once the cake is completely cooled, gently unroll it. Spread the frosting over the entire surface of the cake. Top with a layer of sprinkles.
Carefully reroll the cake, keeping it tucked tight as you roll.
Chill the cake for at least 30 minutes.
In a microwave safe bowl, combine 1 cup white chocolate chips and 3 tablespoon heavy cream.
Heat for 30 seconds at a time and stir well between each interval, until all chips have melted.
Pour the white chocolate ganache over the cake and use a spatula to help spread if needed to coat the whole surface.
Top with the remaining sprinkles.
Place the cake in the fridge until ready to serve. The ganache will solidify slightly once chilled.