First, preheat the oven to 330°F (165°C) on Bake. Line the bottom of an 8-inch pan with parchment paper.

Next, beat the egg whites slightly add sugar until glossy and fluffy. The peaks should be soft but stable.

Meanwhile, beat the egg yolks with the caramel sauce until smooth and creamy.

Then, add the oil and cold water to the yolk mixture and mix until fully combined.

After that, whisk the flour and baking powder together. Add the dry ingredients to the yolk mixture and mix until smooth.

Add the dry ingredients to the yolk mixture

Now, combine the whipped egg whites with the yolk batter. You can fold by hand or mix briefly on low speed. Work gently and do not overmix.

Finally, pour the batter into the pan with parchment paper.

Bake for 25-30 minutes on Bake.

If your oven allows, switch to Convection at the same temperature for the 25-30 minutes more minutes to finish baking evenly, or continue stay on Bake mode.

TOTAL 50-60 minutes in the oven.

Cool the cake completely, before remove from the pan.

First, add the cold heavy cream and dulce de leche to the mixing bowl at the same time.

Then, start mixing on low speed until smooth.

Next, gradually increase the speed and whip until firm, smooth peaks form.

The cream should stay light, stable, and easy to pipe.

First, mix the water with caramel sauce or dulce de leche until smooth.

Then, taste and adjust sweetness if needed.

This step keeps the cake extra moist and tender.

First, slice the chilled sponge into 3 even layers.

Next, place the first layer on a serving plate or cake board and brush generously with soaking syrup.

Then, spread cream on top ( in about 1/2 inch tall) and sprinkle chopped walnuts evenly.

After that, repeat with the second layer, syrup, cream, and walnuts.

Finally, place the last layer on top, soak lightly, frost the cake, and decorate with remaining walnuts.

Refrigerate for 1–2 hours before serving.

You can crumb coat the cake with cake scraper right away, using the same cream you used for the filling, applying a thin.

Alternatively (and this is recommended for best results), wrap the assembled cake tightly in plastic wrap and refrigerate it for a few hours or overnight.

Once chilled, apply a thin final layer of cream for a smoother finish. (See the video for detailed steps.)

For decoration, pipe simple swirls on top using the same cream and finish with a sprinkle of chopped nuts.