1-Step One: Prepare Your Equipment and Oven Start by preheating your oven to 350°F (180°C). This temperature allows the sponge to bake quickly and evenly, developing a tender crumb without drying out. While the oven heats, prepare your 15x10x1 inch jelly roll pan by lightly oiling it and lining with parchment paper. The oil helps the parchment stay in place, and the paper prevents sticking while allowing easy release after baking.

2-Step Two: Separate and Whip the Eggs Separate your eggs carefully, placing whites in one clean, grease-free bowl and yolks in another. Even a tiny amount of yolk in the whites will prevent them from whipping properly, so take your time with this step. Add half the granulated sugar (50g) to the egg whites and whip with an electric mixer until medium-stiff peaks form. The whites should hold their shape when the beaters are lifted but still have a slight curl at the tip. Set this aside while you work on the yolks.

3-Step Three: Whip the Yolks In a separate bowl, combine the egg yolks, remaining 50g of sugar, vanilla paste or extract, vegetable oil, and salt. Whip this mixture on medium-high speed for about 4 minutes until it triples in volume and becomes pale yellow and thick. Properly whipped yolks are essential for creating the light, airy texture that makes this sponge perfect for rolling.

4-Step Four: Combine and Fold Now comes the gentle part. Add the whipped egg whites to the yolk mixture in three parts, folding gently with a spatula after each addition. Use a cutting motion through the center of the batter, then sweep around the edge, rotating the bowl as you go. This technique maintains the air bubbles you’ve worked to create. Once the whites are incorporated, sift the cake flour over the batter in two or three additions. Fold gently after each sifting, working from the bottom of the bowl to the top. Stop folding as soon as no flour streaks remain. Overmixing at this stage will deflate the batter and result in a tough sponge.

5-Step Five: Bake the Sponge Pour the batter into your prepared pan and spread it evenly to all corners using an offset spatula. The layer should be thin and uniform. Bake for 10-12 minutes, checking at the 10-minute mark. The sponge is done when it springs back lightly when pressed in the center and the edges are just beginning to pull away from the sides.

6-Step Six: Roll and Cool the Sponge This step is crucial for preventing cracks. As soon as the sponge comes out of the oven, invert it onto a clean kitchen towel that’s been dusted with powdered sugar. Carefully peel off the parchment paper, then dust the top of the sponge with more powdered sugar. Starting from the short end, roll the sponge up tightly with the towel inside. Allow it to cool completely in this rolled position, which trains the cake to hold its shape.

7-Step Seven: Prepare the Mascarpone Filling While the sponge cools, make the filling. In a mixing bowl, combine the mascarpone cheese, powdered sugar, vanilla paste or extract, and salt. Mix at low speed just until combined. Gradually add the heavy cream while whisking, increasing speed as the mixture thickens. Continue until stiff peaks form, being careful not to over-whip, which can cause the cream to separate.

8-Step Eight: Assemble the Roll Gently unroll the cooled sponge. Combine the cooled coffee with the liqueur if using, and drizzle it evenly over the sponge in small amounts. Allow the coffee to soak in for about 30 seconds before adding more. Spread half of the mascarpone filling over the sponge, leaving a small border around the edges. Carefully re-roll the sponge without the towel, keeping it snug but not tight enough to squeeze out the filling.

9-Step Nine: Finish and Chill Place the roll seam-side down on your serving platter. Pipe the remaining mascarpone cream on top in decorative swirls or stripes. Dust generously with cocoa powder using a fine-mesh sieve. Refrigerate for at least 60 minutes before serving to allow the flavors to meld and the roll to set. For the best results, chill for 4 hours or overnight.