Step 1: Prepare the Oven and Pan

Preheat your oven to 350°F (175°C). Line a 15×10-inch jelly roll pan with parchment paper to ensure the cake does not stick.

Step 2: Mix Dry Ingredients

In a medium bowl, combine the all-purpose flour, baking powder, and salt. Mix well and set aside for later use.

Step 3: Beat Eggs and Sugar

In a large mixing bowl, use an electric mixer to beat together the eggs and granulated sugar until the mixture is thick and pale, which should take about 5-7 minutes.

Step 4: Combine Wet and Dry Ingredients

Gently fold the dry ingredients into the egg mixture. Then, add cocoa powder and vanilla extract, mixing until everything is combined while maintaining an airy batter.

Step 5: Bake the Cake

Pour the batter into the prepared pan and spread it evenly. Bake in the preheated oven for 12-15 minutes, or until the cake springs back when touched.

Step 6: Roll the Cake

Once baked, invert the hot cake onto a kitchen towel dusted with powdered sugar. Carefully roll up the cake with the towel starting from one end. Allow it to cool completely in this rolled shape.

Step 7: Unroll the Cake

After the cake has cooled, gently unroll it and spread a generous layer of Nutella evenly over the surface.

Step 8: Add Caramel and Hazelnuts

Drizzle caramel sauce on top of the Nutella layer, then sprinkle with chopped hazelnuts to add a delightful crunch.

Step 9: Roll the Cake Again

Roll the cake back up without the towel, wrap it in plastic wrap, and chill it in the refrigerator for at least one hour to set.

Step 10: Slice and Serve

After chilling, slice the cake roll into desired pieces. Serve it up and enjoy the rich layers with each gooey, indulgent bite!