Preheat oven on 350F/180C.
Place butter in a small sauce pan and heat on low until melted. Set aside.
Then, separate egg yolks from egg whites in two mixing bowls, using your egg separator.
In the first mixing bowl, beat the egg yolks with sugar, until light and double in size (about 4-5 minutes on Medium speed).
Then, add the flour, corn starch and melted butter.
In the second mixing bowl, whip the egg whites until stiff peaks. Then, using a spatula carefully fold it into your first preparation.
Place your Deep Flexiflat® on the top of your medium perforated baking sheet.
Gently pour your preparation on the Flexiflat®, by letting it glide to the corners. And tap the bottom gently to air the bubbles out.
Bake for 10 minutes at 350F/180C, until the genoise springs back when touched lightly. (Every oven heats differently, monitor your genoise from 8min)
While your cake is baking, place your mixing bowl and whisk in the freezer.
Remove from oven and let cool in the Flexiflat® for 5 minutes before flipping onto your bonMAT™.
Place your bonMAT™ on top of your genoise and flip to release the cake from the Flexiflat™. Gently start with the corners to release and pull the Flexiflat® away from the cake. Roll the genoise with the bonMAT™ to create a fairly tight roll. Allow the genoise to cool completely in the refrigerator for about 30 minutes.
Once your roll has cooled down, gently unroll from the bonMAT™. Spread jam thinly over your genoise.
Take your mixing bowl out of the freezer, whip your cream until stiff peaks. Then, using a spatula carefully spread it onto the jam.
Sprinkle your raspberry halves on top of the cream.
Use your bonMAT™ as a guide to roll back your genoise, and transfer to your serving plate. Store in the refrigerator until it is time to eat. Enjoy & Bon Appetit!
OPTIONAL: You can sprinkle the top of your cake roll with powdered sugar.