In a large bowl, add the egg whites and cream of tartar. Whip using a stand mixer or hand mixer until stiff peaks form.
In another large bowl, add the rest of the ingredients. Mix with a whisk. The batter will be pretty thick.
Add ⅙ of the meringue to the egg yolk batter and mix with a hand mixer until the batter starts to be thinner. Add another ⅙ and mix with the hand mixer again.At this stage, add ⅙ of the meringue at a time, but fold it in with a silicone spatula. Make sure you don't over mix or you'll break the air bubbles and have a flatter cake.
Add a piece of parchment paper over a baking pan.
Spread the batter evenly onto the prepared baking pan and bake for 13 minutes, until the top springs back when touched.Remove the pan from the oven and let cool for a minute. Put a kitchen towel to the side and lift up the parchment paper and flip on its other side onto the kitchen towel. The parchment paper side should now be side up.Carefully peel away the parchment paper from the sponge cake. Place the parchment paper over again and gently roll up inside the kitchen towel while still warm. We want the cake to cool down in its rolled up form to prevent cracking. Set aside until completely cooled.
Add the cream cheese and ½ cup of heavy cream to a mixing bowl. Mix with a hand mixer until smooth and creamy. Add the stevia powder and vanilla and continue to mix. Slowly add the heavy cream ¼ cup at a time to the bowl and whip for 3-5 minutes with a hand mixer until it starts to thicken.
Once thickened, your roll cake is ready to be filled.
Carefully unroll the cake and peel off the parchment paper. Spread the cream cheese whipping cream all over evenly.Roll the cake up once more and it's done!You can cut off the edges if you want a clean cut and you can also refrigerate before serving so that it's nice and cool! Sprinkle some of the cinnamon powder over and it's ready to serve!
I have tried making it without the whey protein isolate powder, it works but it turned out a bit flatter than the final version.