Combine 4 eggs and the sugar into the bowl of a stand mixer or a large mixing bowl if using a hand held mixer or whipping by hand. Use the whisk attachment and whip on the highest speed for at least 5 minutes.
You will see the mixture lighten up to a pale yellow and after the 5 minutes, do the ribbon test (see notes). If the batter is not quite at the ribbon stage, continue beating for another few minutes or until it gets to the ribbon stage
Once the batter is to the ribbon stage, add in the vanilla and mix for a few seconds until combined.
Sift ¼ cup of flour at a time and gently fold the flour into the batter. You do not want to mix this batter with the mixer, the folding technique is important to keep the batter aerated so your cake doesn't fall. Fold just until you can no longer see the flour and then continue with these steps until all the flour is incorporated.
Spread some butter or oil on a 13x13 pan and place a piece of parchment on top allowing the parchment to also cover the edges. Trim of any excess.
Pour the batter onto the parchment paper and gently spread the batter so it is even. Place the pan into the Ninja Foodi Digital Air Fry Oven and bake on 325°F/160°C for 10-12 minutes or until the top is lightly brown and the cake is fully cooked.
Cool for about 5 minutes and then roll the cake with the parchment on. Place on a cooling rack and let cool while you make the filling.
Vanilla Buttercream
Add the heavy cream to the bowl of a stand mixer and with the whisk attachment beat on high speed until the cream thickens into whipped cream
Add the butter and the vanilla and beat until combined.
Add the powdered sugar and beat on medium high speed until the buttercream is smooth.
Assembly
Unroll the cooled cake and spread the buttercream all over the cake. Reserve about ½ cup if you want to put some of the buttercream on top for adding decorations. Spread the strawberry preserves over the top of the buttercream.
Roll the cake and remove the parchment paper as you go. If the parchment is sticking, use a knife to gently separate it from the cake.
Once the cake is rolled, place it seam side down on a platter or on parchment on a cooling rack and chill for about 4 hours.
Slice into thin slices and serve. Enjoy!
Video
Notes
The ribbon test is when you allow some of the batter from the whisk to fall back over the top of the batter and it holds it shape for about 3-5 seconds or so. If the batter disappears quickly, you need to whisk the mixture longer.